# ZeroTool > Free online developer tools. No sign-up. Each tool explains how it processes input and any requests to other services. ZeroTool (https://zerotool.dev) has 141 free developer tools. Each tool is one web page; there is no account and no API. - Tool pages are at https://zerotool.dev/tools/{slug}/ in English and at /zh/tools/{slug}/, /ja/tools/{slug}/ and /ko/tools/{slug}/ in Chinese, Japanese and Korean. The same tools are listed with their names in those languages in the files under "Other languages". - The tools process the text, files and keys you give them with JavaScript in your browser tab and do not upload them. - These tools send requests because of what they do: - [DNS Lookup](https://zerotool.dev/tools/dns-lookup/): Lookups send the domain name to the DNS resolver you pick (Cloudflare or Google). - [QR Code Reader](https://zerotool.dev/tools/qr-code-decoder/): Images and camera frames are decoded on this page; URL mode requests the image from the host at the address you enter. - [Markdown Preview](https://zerotool.dev/tools/markdown-preview/): Markdown is rendered on this page; web images load from their URLs, and the image hosts receive those requests. - [Meta Tag Generator](https://zerotool.dev/tools/meta-tag-generator/): Tags are generated on this page; Facebook, Twitter and Discord previews request the image URLs you enter from their hosts. - This tool uses the network only after you turn on an option: - [Markdown to Word Converter](https://zerotool.dev/tools/markdown-to-word/): export downloads http(s) images from their hosts only when Embed web images is enabled. - Most pages load Google Analytics 4 (page views, and tool-use events that record the tool name and action, not your input) and Google AdSense. Pages for tools that handle credentials, keys, tokens, or private files and text load neither: [AES Encryption & Decryption](https://zerotool.dev/tools/aes-encrypt-decrypt/), [Basic Auth Header Generator](https://zerotool.dev/tools/basic-auth-header-generator/), [Bcrypt Generator & Checker](https://zerotool.dev/tools/bcrypt-generator/), [Cookie Parser & Decoder](https://zerotool.dev/tools/cookie-parser/), [CSR Decoder](https://zerotool.dev/tools/csr-decoder/), [cURL to Code Converter](https://zerotool.dev/tools/curl-to-code/), [Docker Run to Compose](https://zerotool.dev/tools/docker-to-compose/), [Env File Parser](https://zerotool.dev/tools/env-file-parser/), [EXIF Metadata Viewer](https://zerotool.dev/tools/exif-metadata-viewer/), [File Hash Checker](https://zerotool.dev/tools/file-hash-checker/), [HAR Analyzer & Viewer](https://zerotool.dev/tools/har-file-analyzer/), [Hash Generator](https://zerotool.dev/tools/hash-generator/), [HMAC SHA256 Generator](https://zerotool.dev/tools/hmac-generator/), [htpasswd Generator](https://zerotool.dev/tools/htpasswd-generator/), [HTTP Header Analyzer](https://zerotool.dev/tools/http-header-analyzer/), [IBAN Validator & Parser](https://zerotool.dev/tools/iban-validator-parser/), [Image Compressor](https://zerotool.dev/tools/image-compressor/), [JWT Decoder](https://zerotool.dev/tools/jwt-decoder/), [JWT Generator / Signer](https://zerotool.dev/tools/jwt-generator/), [Password Generator](https://zerotool.dev/tools/password-generator/), [Pixelate Image](https://zerotool.dev/tools/pixelate-image/), [PKCE Generator](https://zerotool.dev/tools/pkce-generator/), [RSA Key Pair Generator](https://zerotool.dev/tools/rsa-key-generator/), [Redact API Keys & Secrets](https://zerotool.dev/tools/secret-redactor/), [SQLite Viewer](https://zerotool.dev/tools/sqlite-viewer/), [TOTP Generator](https://zerotool.dev/tools/totp-generator/), [WiFi QR Code Generator](https://zerotool.dev/tools/wifi-qr-code-generator/), [Invisible Character Detector](https://zerotool.dev/tools/zero-width-character-detector/). - Source code: https://github.com/kassol/zerotool-dev ## JSON & Data - [CSV to JSON Converter](https://zerotool.dev/tools/csv-json/): Convert CSV to JSON and JSON to CSV instantly. Handles quoted fields, reads the first row as the header. - [CSV to SQL Converter](https://zerotool.dev/tools/csv-to-sql/): Convert CSV data to SQL INSERT statements. Supports MySQL, PostgreSQL, SQLite dialects, batch and individual insert modes, NULL handling, proper escaping. Runs in your browser. - [jq Playground](https://zerotool.dev/tools/jq-playground/): Run jq 1.7.1 filters in your browser with -r, -s, -n, --arg and JSON Lines input. Output, stderr and exit codes match the jq command line; errors point to the bad spot. - [JSON Diff](https://zerotool.dev/tools/json-diff/): Compare two JSON objects and visualize differences. Outputs RFC 6902 JSON Patch and a color-coded tree diff. - [JSON Formatter](https://zerotool.dev/tools/json-formatter/): Format, minify and validate JSON in your browser. Keeps big numbers exact, flags duplicate keys and converts JSON5 or JSONC with comments. - [JSON Schema Validator](https://zerotool.dev/tools/json-schema-validator/): Validate JSON, YAML or JSON Lines against a JSON Schema (draft-04 to 2020-12). Errors are grouped by data path and linked to the line and the schema keyword. - [JSON to CSV Converter](https://zerotool.dev/tools/json-to-csv/): Convert JSON arrays to CSV instantly. Supports nested object flattening (dot-path), custom delimiters, and RFC 4180 escaping. Runs in your browser. - [JSON to JSON Schema](https://zerotool.dev/tools/json-to-json-schema/): Paste JSON and instantly generate a JSON Schema draft-07. Infers types, required fields, and nested objects or arrays. - [JSON to XML Converter](https://zerotool.dev/tools/json-xml-converter/): Convert JSON to XML and XML to JSON instantly. Customizable root element, pretty-print toggle, and real-time conversion. Runs in your browser, no upload required. - [JSONL Converter](https://zerotool.dev/tools/jsonl-converter/): Convert JSONL/NDJSON to JSON arrays and JSON arrays back to JSON Lines. Validate each line, locate parse errors, and export valid records. Runs in your browser. - [JSONPath Tester](https://zerotool.dev/tools/jsonpath-tester/): Test JSONPath expressions against JSON data in real time. View matched results with syntax highlighting. Supports filters, wildcards, and recursive descent. - [Protobuf to JSON](https://zerotool.dev/tools/protobuf-to-json/): Decode Protobuf binary (hex, Base64, gRPC frames) to ProtoJSON with or without a .proto schema, encode JSON back to bytes and print sample JSON. Runs in your browser. - [SQLite Viewer](https://zerotool.dev/tools/sqlite-viewer/): Open .db / .sqlite files in your browser: browse tables, views and indexes, run SQL, export CSV. Nothing is uploaded. - [TOML to JSON Converter](https://zerotool.dev/tools/toml-json/): Convert between TOML and JSON formats instantly with validation. - [XML Formatter](https://zerotool.dev/tools/xml-formatter/): Format, beautify, and minify XML documents with syntax validation. - [YAML to JSON Converter](https://zerotool.dev/tools/yaml-json/): Convert YAML to JSON and JSON to YAML instantly. Supports nested objects, arrays, and all YAML 1.2 features. - [YAML to TOML Converter](https://zerotool.dev/tools/yaml-toml/): Convert YAML to TOML and TOML to YAML instantly. Handles nested objects, arrays, and all common data types. Free, browser-based, no upload required. - [YAML Validator](https://zerotool.dev/tools/yaml-validator/): Validate YAML syntax online — detailed error messages with line and column numbers, plus parsed structure preview. Runs in your browser. ## Code & Types - [cURL to Code Converter](https://zerotool.dev/tools/curl-to-code/): Convert cURL commands to Python, JavaScript, Go, PHP, and Node.js code instantly. - [GraphQL Formatter](https://zerotool.dev/tools/graphql-formatter/): Format, beautify, minify, and validate GraphQL queries, mutations, and SDL schemas. Locate syntax errors with line and column. Runs in your browser, no upload. - [HTML Minifier & Beautifier](https://zerotool.dev/tools/html-minifier/): Minify or beautify HTML markup in your browser. Strip comments, collapse whitespace, or re-indent — instant, no upload, no signup. - [HTML to JSX Converter](https://zerotool.dev/tools/html-to-jsx/): Convert HTML to React JSX instantly in your browser. Handles className, htmlFor, inline style objects, camelCase events, self-closing tags, and comments. Runs in your browser. - [JSON to Go Struct](https://zerotool.dev/tools/json-to-go-struct/): Generate Go structs with json tags from JSON. Handles nested objects, arrays, and nullable fields as pointers. - [JSON to Java POJO](https://zerotool.dev/tools/json-to-java-pojo/): Generate Java POJO classes from JSON. Supports Jackson, Gson, and Lombok annotations. Handles nested objects and arrays. - [JSON to Kotlin Data Class](https://zerotool.dev/tools/json-to-kotlin/): Generate Kotlin data classes from JSON. Handles nested objects, arrays, and nullable fields. Supports custom root class name. - [JSON to Mongoose Schema](https://zerotool.dev/tools/json-to-mongoose/): Generate Mongoose schema definitions from JSON. Supports JavaScript and TypeScript output, timestamps option, nested objects, and arrays. Runs in your browser. - [JSON to Python Dataclass](https://zerotool.dev/tools/json-to-python-dataclass/): Generate Python dataclasses from JSON. Supports @dataclass, Pydantic v2 BaseModel, and TypedDict. Handles nested objects, arrays, and optional fields. - [JSON to TypeScript Generator](https://zerotool.dev/tools/json-to-typescript/): Generate TypeScript interfaces from JSON. Handles nested objects, arrays, unions, and optional properties. - [JSON to Zod Schema](https://zerotool.dev/tools/json-to-zod/): Generate Zod validation schemas from JSON data. Handles nested objects, arrays, and optional properties. - [JavaScript Keycode Explorer](https://zerotool.dev/tools/keycode-explorer/): Press any key in your browser to instantly see event.key, event.code, keyCode, charCode, location, repeat, and modifier states — plus a ready-to-copy JS snippet. Runs in your browser. - [OpenAPI to TypeScript Generator](https://zerotool.dev/tools/openapi-to-typescript/): Generate TypeScript interfaces from OpenAPI 3.0/3.1 specs in YAML or JSON. Supports $ref, oneOf/anyOf/allOf, enums, nullable, and optional Zod schemas. Runs in your browser. - [Regex Tester](https://zerotool.dev/tools/regex-tester/): Test regular expressions in real time with match highlighting and capture group details. - [SQL Formatter](https://zerotool.dev/tools/sql-formatter/): Format, beautify, and minify SQL queries with syntax highlighting. - [SVG to JSX Converter](https://zerotool.dev/tools/svg-to-jsx/): Convert SVG to a React JSX component instantly. Handles camelCase attributes, className, xmlns cleanup. Optional TypeScript, forwardRef, and memo wrapping. Runs in your browser. - [TypeScript to Zod Schema](https://zerotool.dev/tools/typescript-to-zod/): Convert TypeScript interfaces and type aliases to Zod validation schemas. Handles unions, optional fields, arrays, nested objects, and enums. Runs in your browser. ## Text & Markdown - [AI Token Counter](https://zerotool.dev/tools/ai-token-counter/): Count tokens with the exact OpenAI (o200k_base, cl100k_base) and DeepSeek V4 tokenizers in your browser, see every token, and estimate GPT, Claude, Gemini and DeepSeek API cost. - [CSV to Markdown Table](https://zerotool.dev/tools/csv-to-markdown/): Convert CSV to a Markdown table instantly. Supports quoted fields, uses the first row as the header, and lets you choose left, center, or right column alignment. - [Diff Checker](https://zerotool.dev/tools/diff-checker/): Compare two texts line by line and highlight additions and deletions. Powered by LCS algorithm. - [HTML to Markdown Converter](https://zerotool.dev/tools/html-to-markdown/): Convert HTML to Markdown instantly in your browser. Preserves headings, bold, italic, links, images, code blocks with language tags, GFM tables, and nested lists. Runs in your browser. - [Line Tools](https://zerotool.dev/tools/line-tools/): Remove duplicate lines, sort alphabetically or numerically, reverse, shuffle, and trim text lines. - [Lorem Ipsum Generator](https://zerotool.dev/tools/lorem-ipsum/): Generate Lorem Ipsum placeholder text instantly. Choose paragraph count and copy to clipboard. - [Markdown Linter](https://zerotool.dev/tools/markdown-linter/): Check Markdown for style and formatting errors in real time. Shows rule IDs, line numbers, and clickable results. Runs in your browser; your Markdown is not uploaded or saved. - [Markdown Preview](https://zerotool.dev/tools/markdown-preview/): Live Markdown editor with real-time HTML preview. Supports GFM tables, task lists, and code blocks. Network: Markdown is rendered on this page; web images load from their URLs, and the image hosts receive those requests. - [Markdown Table Generator](https://zerotool.dev/tools/markdown-table-generator/): Edit a GitHub-flavored Markdown table in a grid or paste it from Excel, Google Sheets, CSV, JSON or HTML. Pipes and line breaks are escaped; CJK columns line up. - [Markdown to Word Converter](https://zerotool.dev/tools/markdown-to-word/): Convert Markdown to a Word .docx in your browser with heading styles, Word numbering, tables, task lists, footnotes and images. Your Markdown is not uploaded. Network: export downloads http(s) images from their hosts only when Embed web images is enabled. - [Markdown TOC Generator](https://zerotool.dev/tools/markdown-toc-generator/): Build a clickable table of contents from Markdown headings. Supports GitHub, GitLab, Jekyll, and Bitbucket anchor styles, heading-level filtering, and in-place TOC updates via markers. Runs in your browser. - [Slugify String](https://zerotool.dev/tools/slugify/): Convert any text to a URL-friendly slug. Handles Unicode, removes special characters, custom separator support. - [String Escape / Unescape](https://zerotool.dev/tools/string-escape/): Escape and unescape strings for JSON, JavaScript, Java, C, Python, HTML, XML, CSV, SQL, regex and shell. Invalid escapes are reported with their position. - [Text Case Converter](https://zerotool.dev/tools/text-case/): Convert text to UPPER, lower, Title, camelCase, snake_case, and more. - [Text to ASCII Art Generator](https://zerotool.dev/tools/text-to-ascii-art/): Turn text into FIGlet ASCII art banners with 12 fonts. Output matches the figlet command line; set spacing and width, copy as code comments or Markdown, download TXT or PNG. - [Fancy Text Generator](https://zerotool.dev/tools/unicode-text-converter/): Turn text into 23 Unicode fancy fonts — bold, italic, cursive, Fraktur, small caps, circled — and turn fancy text back into plain letters. Accents and emoji stay intact. - [Word & Character Counter](https://zerotool.dev/tools/word-counter/): Count words, characters, sentences, and paragraphs. Estimate reading and speaking time. - [Invisible Character Detector](https://zerotool.dev/tools/zero-width-character-detector/): Find and remove zero-width spaces, BOMs, bidi controls and tag characters, and decode messages hidden by common zero-width steganography tools. Removal modes let you keep emoji joiners and variation selectors. ## Encoding - [ASCII Converter](https://zerotool.dev/tools/ascii-converter/): Convert between text and ASCII codes. Supports decimal, hex, octal, and binary representations. - [Base64 Encode / Decode](https://zerotool.dev/tools/base64/): Encode text to Base64 or decode Base64 back to plain text. - [HTML Entity Encoder / Decoder](https://zerotool.dev/tools/html-entity/): Encode and decode HTML entities. Supports named, decimal, and hex entities. - [Image to Base64 Converter](https://zerotool.dev/tools/image-to-base64/): Convert images to Base64, data URIs, CSS, HTML or Markdown, and Base64 back to images. The type comes from the file bytes; SVG can be URL-encoded. - [Morse Code Translator](https://zerotool.dev/tools/morse-code-translator/): Translate text to Morse code and Morse code back to text. Supports letters, numbers, and common punctuation. - [NATO Phonetic Alphabet](https://zerotool.dev/tools/nato-phonetic-alphabet/): Convert text to NATO phonetic alphabet codes (Alfa, Bravo, Charlie…). Supports letters and digits. Word and table output modes. Runs in your browser. - [Binary to Decimal & Hex Converter](https://zerotool.dev/tools/number-base/): Convert binary, decimal, hex, octal and any base 2–36. Exact for large numbers, fractions and two's complement; points to the first bad digit. - [Text to Binary Translator](https://zerotool.dev/tools/text-to-binary/): Translate text to 8-bit binary (UTF-8) and binary back to text. Reads spaced, continuous and bin() output; points to bad bits and invalid bytes. - [URL Encode / Decode](https://zerotool.dev/tools/url-encode/): Encode or decode URL components and query strings. ## Crypto & Auth - [AES Encryption & Decryption](https://zerotool.dev/tools/aes-encrypt-decrypt/): Encrypt and decrypt text or files with AES-256-GCM in your browser. Use a password (PBKDF2, 600,000 iterations) or a raw 128/192/256-bit key. Nothing is uploaded. - [Basic Auth Header Generator](https://zerotool.dev/tools/basic-auth-header-generator/): Generate and decode HTTP Basic Authentication headers in your browser. Copy Authorization headers, tokens, cURL snippets, and Fetch examples with no upload. - [Bcrypt Generator & Checker](https://zerotool.dev/tools/bcrypt-generator/): Generate and check bcrypt hashes in your browser. Pick $2b$, $2y$ or $2a$ and a cost from 4 to 31, see the 72-byte limit, and find out which of PHP, Laravel, Node.js, Python, Go and Spring accept a hash. - [CSR Decoder](https://zerotool.dev/tools/csr-decoder/): Decode a PKCS#10 certificate signing request — Subject, public key, requested SANs and extensions — and verify its self-signature before you send it to a CA. Runs in your browser. - [File Hash Checker](https://zerotool.dev/tools/file-hash-checker/): Get the SHA-256, SHA-1, SHA-384, SHA-512, MD5 or CRC32 of local files of any size and check them against a hash or a SHA256SUMS list. Files are not uploaded or saved. - [Hash Generator](https://zerotool.dev/tools/hash-generator/): Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text. - [HMAC SHA256 Generator](https://zerotool.dev/tools/hmac-generator/): Compute HMAC-SHA256, SHA-512, SHA-1 or MD5 from text, hex or Base64 keys, and check GitHub, Stripe, Slack, LINE, Feishu or DingTalk webhook signatures in your browser. - [htpasswd Generator](https://zerotool.dev/tools/htpasswd-generator/): Generate htpasswd lines for Apache and Nginx in bcrypt $2y$, SHA-512 crypt, APR1 and legacy formats, see which servers read each format, and check a password against an existing htpasswd file. Hashing runs in your browser. - [JWT Decoder](https://zerotool.dev/tools/jwt-decoder/): Decode and inspect JWT header, payload, and signature. Highlights expiry status and timestamp claims. - [JWT Generator / Signer](https://zerotool.dev/tools/jwt-generator/): Generate and sign JWT tokens (HS256, HS384, HS512) in your browser. Paste or edit header and payload JSON, set your secret, and copy the signed token. - [Password Generator](https://zerotool.dev/tools/password-generator/): Generate cryptographically secure passwords. Customize length and character sets with entropy meter. - [PKCE Generator](https://zerotool.dev/tools/pkce-generator/): Generate an RFC 7636 PKCE code_verifier and S256 code_challenge, check why a challenge does not match, and build the authorization URL and token cURL. The verifier is not sent or saved. - [RSA Key Pair Generator](https://zerotool.dev/tools/rsa-key-generator/): Generate RSA key pairs (2048/4096-bit) in PEM or JWK format. Keys are generated in your browser and are not uploaded. - [Redact API Keys & Secrets](https://zerotool.dev/tools/secret-redactor/): Mask API keys, tokens, private keys and passwords in logs before pasting into AI chat, then restore them in the reply. - [SSL Certificate Decoder](https://zerotool.dev/tools/ssl-certificate-decoder/): Decode X.509 certificates and whole chains from PEM, Base64, DER or PKCS #7: SANs, validity, key, extensions, SCTs and fingerprints, plus chain order and signature checks. - [TOTP Generator](https://zerotool.dev/tools/totp-generator/): Generate RFC 6238 TOTP codes from a Base32 secret or otpauth:// URI, with countdown, previous and next codes, QR code, and a clock check. ## Web & HTTP - [Cookie Parser & Decoder](https://zerotool.dev/tools/cookie-parser/): Read a Cookie header, Set-Cookie lines or cookies.txt: decoded values, which cookies a browser keeps or rejects and why, the next request's Cookie header, and a redacted copy. - [CSP Header Generator](https://zerotool.dev/tools/csp-header-generator/): Build a Content-Security-Policy header from directives, hosts, hashes, and nonces. Strict-mode templates with report-only fallback, plus Express and Nginx snippets. Runs in your browser. - [DNS Lookup](https://zerotool.dev/tools/dns-lookup/): Look up A, AAAA, CNAME, MX, TXT, NS, SOA, CAA, PTR and SRV records over DNS-over-HTTPS. Your browser asks Cloudflare or Google directly, with no ZeroTool server in between. Network: Lookups send the domain name to the DNS resolver you pick (Cloudflare or Google). - [HAR Analyzer & Viewer](https://zerotool.dev/tools/har-file-analyzer/): Open a HAR file from Chrome, Firefox or Safari DevTools: sortable waterfall, request details and cURL, slow and failed requests, and a redacted copy without cookies or tokens. - [.htaccess Generator](https://zerotool.dev/tools/htaccess-generator/): Generate Apache .htaccess configurations online. Force HTTPS, set caching, block directory listing, add custom redirects. Runs in your browser. - [HTTP Header Analyzer](https://zerotool.dev/tools/http-header-analyzer/): Paste raw HTTP request or response headers and instantly inspect security, caching, CORS, content, and auth metadata. 88 header descriptions with configuration hints, JSON export. Runs in your browser. - [HTTP Status Codes](https://zerotool.dev/tools/http-status-codes/): Searchable reference for all HTTP status codes (1xx–5xx) with descriptions and use cases. - [IP Subnet Calculator](https://zerotool.dev/tools/ip-subnet-calculator/): Calculate IPv4 subnet details from IP + CIDR. Outputs network address, broadcast, first/last host, usable hosts, subnet mask, and wildcard mask. Runs in your browser. - [Meta Tag Generator](https://zerotool.dev/tools/meta-tag-generator/): Build a complete block — Open Graph, Twitter Card, Schema.org JSON-LD, and SEO basics — with live previews for Google, Facebook, Twitter, and Discord. Network: Tags are generated on this page; Facebook, Twitter and Discord previews request the image URLs you enter from their hosts. - [MIME Type Lookup](https://zerotool.dev/tools/mime-type-lookup/): Find the exact MIME type for any file extension and reverse-search by Content-Type. Includes a magic-bytes sniffer that detects file type in your browser — files are not uploaded. - [OpenAPI Validator](https://zerotool.dev/tools/openapi-validator/): Validate OpenAPI 3.0, 3.1, 3.2 and Swagger 2.0 (YAML or JSON) with line numbers: official schemas, $ref across files, path parameters, security schemes and examples. Nothing is uploaded. - [Robots.txt Generator](https://zerotool.dev/tools/robots-txt-generator/): Generate robots.txt files online. Configure user-agent rules, allow/disallow paths, and sitemap URLs. Runs in your browser. - [URL Parser](https://zerotool.dev/tools/url-parser/): Split a URL into scheme, host, port, path, query and fragment with your browser's parser, see what it changed and where RFC 3986 reads it differently, and edit parameters. ## CSS - [CSS Box Shadow Generator](https://zerotool.dev/tools/box-shadow-generator/): Generate CSS box-shadow values visually. Adjust horizontal offset, vertical offset, blur, spread, opacity, color, and inset mode with sliders. Live preview and one-click copy. - [CSS Clamp Calculator](https://zerotool.dev/tools/css-clamp-calculator/): Generate responsive CSS clamp() values for fluid typography and spacing with live previews. Runs in your browser. - [CSS Clip-Path Generator](https://zerotool.dev/tools/css-clip-path-generator/): Build CSS clip-path shapes by dragging polygon points or setting circle, ellipse and inset values. Keeps two decimals, supports arrow-key editing, and previews path(), shape() and reference boxes in your browser. - [CSS Filter Generator](https://zerotool.dev/tools/css-filter-generator/): Generate CSS filter effects visually. Adjust blur, brightness, contrast, grayscale, hue-rotate, invert, opacity, saturate, and sepia with sliders. Live preview with custom image upload. Free online CSS filter generator. - [CSS Flexbox Generator](https://zerotool.dev/tools/css-flexbox-generator/): Build CSS Flexbox layouts visually. Configure flex direction, wrap, justify-content, align-items, and gap with a live preview. - [CSS Gradient Generator](https://zerotool.dev/tools/css-gradient-generator/): Generate CSS gradients visually. Linear, radial, and conic types. Adjust angle, position, and up to 6 color stops with live preview and instant copy. Free online gradient generator. - [CSS Grid Generator](https://zerotool.dev/tools/css-grid-generator/): Build CSS Grid layouts visually. Set columns, rows, gaps, and template values with live preview and instant code output. - [CSS Specificity Calculator](https://zerotool.dev/tools/css-specificity-calculator/): Calculate CSS selector specificity as (a, b, c) tuples. Compare multiple selectors, visual breakdown by ID, class, and element. - [CSS to Tailwind Converter](https://zerotool.dev/tools/css-to-tailwind/): Convert CSS properties to Tailwind utility classes instantly. - [CSS Triangle Generator](https://zerotool.dev/tools/css-triangle-generator/): Generate CSS triangles in any direction using the border hack. Pick direction, size, and color — get ready-to-use CSS code instantly. Free online css triangle generator online. - [CSS Unit Converter](https://zerotool.dev/tools/css-unit-converter/): Convert between px, rem, em, and vw CSS units instantly. Configurable root font size and viewport width. - [CSS Variables Generator](https://zerotool.dev/tools/css-variables-generator/): Generate CSS custom properties from design tokens. Define colors, typography, spacing, and border radius — output ready-to-use :root variables. - [Cubic Bezier Generator](https://zerotool.dev/tools/cubic-bezier-generator/): Visual editor for CSS cubic-bezier() easing curves. Drag control points, preview the animation live, and copy CSS / SCSS / Tailwind output. Runs in your browser. - [Glassmorphism CSS Generator](https://zerotool.dev/tools/glassmorphism-generator/): Generate frosted-glass CSS or a Tailwind v4 utility. Preview local images, estimate text contrast, and include opaque fallbacks and reduced-transparency rules. ## Color - [Color Blindness Simulator](https://zerotool.dev/tools/color-blindness-simulator/): Simulate 8 types of color vision deficiency on images, screenshots and color palettes. Compare all types side by side, save full-size PNGs and find color pairs that look the same. Runs in your browser; images are not uploaded. - [Color Contrast Checker](https://zerotool.dev/tools/color-contrast-checker/): Check WCAG color contrast ratio for any foreground and background. Get AA/AAA pass-fail for body text, large text, and UI components, plus a one-click "keep hue, fix lightness" suggestion when contrast is too low. - [Color Converter](https://zerotool.dev/tools/color-converter/): Convert colors between HEX, RGB, and HSL formats with a live color preview. - [Color Palette Generator](https://zerotool.dev/tools/color-palette-generator/): Generate complementary, split-complementary, analogous, triadic, tetradic, square and monochromatic palettes from any CSS color on an HSL or OKLCH color wheel. Copy values or export CSS variables, SCSS, Tailwind or JSON. - [Color Shades Generator](https://zerotool.dev/tools/color-shades-generator/): Turn one color into an 11-step 50–950 shade scale in OKLCH. Your color stays exact at its step, each step shows WCAG contrast, and the scale exports to CSS, Tailwind v3/v4, SCSS or JSON. - [Color Picker from Image & Screen](https://zerotool.dev/tools/eyedropper-color-picker/): Pick a color from any pixel on your screen with the browser's native EyeDropper API (Chrome, Edge, Opera) or from an image or pasted screenshot. Get HEX, RGB, HSL, OKLCH and Display P3 that convert back to the same color, with wide-gamut and transparency warnings. - [Image Color Palette Extractor](https://zerotool.dev/tools/image-color-palette/): Extract a color palette from an image with the share of each color. Same image, same palette; exact colors from flat graphics. Copy HEX, RGB, HSL or OKLCH, export CSS, Tailwind, JSON, GIMP .gpl or Adobe .ase. ## Image - [Aspect Ratio Calculator](https://zerotool.dev/tools/aspect-ratio/): Calculate and resize aspect ratios. Lock ratio and scale dimensions proportionally. - [EXIF Metadata Viewer](https://zerotool.dev/tools/exif-metadata-viewer/): View and remove EXIF metadata from JPEG photos online — strip GPS, camera info, and timestamps in your browser. Runs in your browser, no upload. - [Favicon Generator](https://zerotool.dev/tools/favicon-generator/): Generate a complete favicon set from emoji, text, image, or SVG. Outputs ICO, multi-size PNGs, apple-touch-icon, and manifest. Runs in your browser, no upload. - [GIF Compressor](https://zerotool.dev/tools/gif-compressor/): Shrink animated GIFs in your browser with lossy compression, fewer colors, resizing and frame skipping. No upload. - [GIF Splitter](https://zerotool.dev/tools/gif-splitter/): Split an animated GIF into PNG or JPG frames, download them as a ZIP, or build a sprite sheet with JSON. No upload. - [Image Compressor](https://zerotool.dev/tools/image-compressor/): Compress JPEG, PNG, and WebP images in your browser. Adjust quality, resize on the long edge, and shrink file size instantly. Runs in your browser, no upload. - [Image Splitter](https://zerotool.dev/tools/image-splitter/): Split an image into grid tiles, an Instagram grid or a seamless carousel. Download PNG, JPG or WebP in a ZIP. No upload. - [Pixelate Image](https://zerotool.dev/tools/pixelate-image/): Pixelate, blur or black out faces, text and secrets in any image or screenshot. Select areas or the whole image, strip metadata, no upload. - [Sprite Sheet Generator](https://zerotool.dev/tools/sprite-sheet-generator/): Pack images, folders and GIF frames into one PNG or WebP sprite sheet with trim, padding and extrude. Export JSON for Phaser and PixiJS, XML or CSS. No upload. - [SVG Optimizer](https://zerotool.dev/tools/svg-optimizer/): Compress SVG with SVGO 4.1 in your browser: many files to one ZIP, a pixel check of the result and notes on removed IDs, classes or viewBox. No upload. - [SVG to PNG Converter](https://zerotool.dev/tools/svg-to-png-converter/): Convert SVG to PNG, JPEG or WebP in your browser. Scale or set exact pixels, keep transparency, convert many files into one ZIP. No upload. - [WebP Converter](https://zerotool.dev/tools/webp-converter/): Convert PNG/JPG/GIF to WebP and WebP to PNG online. Batch conversion, quality control, file size comparison. Runs in your browser. ## IDs & QR - [Barcode Generator](https://zerotool.dev/tools/barcode-generator/): Generate EAN-13, EAN-8, UPC-A, Code 128, Code 39, and ITF-14 barcodes with automatic check digits. Download SVG or PNG, nothing uploaded. - [Fake Data Generator](https://zerotool.dev/tools/fake-data-generator/): Generate realistic test data: names, emails, addresses, UUIDs, and more. Export as JSON or CSV. - [IBAN Validator & Parser](https://zerotool.dev/tools/iban-validator-parser/): Validate any IBAN with mod-97 checksum and parse it into country, check digits, bank code, branch code, and account number. Covers 80+ countries from the SWIFT IBAN Registry. Runs in your browser. - [Nano ID Generator](https://zerotool.dev/tools/nano-id-generator/): Generate Nano IDs with customizable size (1–128) and alphabet: URL-safe, alphanumeric, hex, numbers-only, or custom. Single or batch up to 100. Runs in your browser. - [QR Code Reader](https://zerotool.dev/tools/qr-code-decoder/): Read QR codes from an image, a pasted screenshot or your camera. Several codes per image, the real host of each link, Shift_JIS and GBK text. Runs in your browser. Network: Images and camera frames are decoded on this page; URL mode requests the image from the host at the address you enter. - [QR Code Generator](https://zerotool.dev/tools/qr-code-generator/): Make static QR codes for links, text, vCard or MECARD contacts, email, phone, SMS and locations. PNG with whole pixels per module, or SVG. - [ULID Generator](https://zerotool.dev/tools/ulid-generator/): Generate ULIDs (Universally Unique Lexicographically Sortable Identifiers). Single or batch (up to 100). Shows timestamp and random components. Built-in ULID decoder. Runs in your browser. - [UUID Generator](https://zerotool.dev/tools/uuid-generator/): Generate v4 UUIDs instantly — single or batch. - [WiFi QR Code Generator](https://zerotool.dev/tools/wifi-qr-code-generator/): Make a Wi-Fi QR code guests join in one scan: escaped name and password, WPA3-only and hidden options, 32-byte and password checks, PNG, SVG and a printable card. ## DevOps & Time - [Chmod Calculator](https://zerotool.dev/tools/chmod-calculator/): Calculate Linux file permissions interactively. Convert between numeric and symbolic notation. - [Cron Job Generator](https://zerotool.dev/tools/cron-job-generator/): Build cron expressions visually with field-by-field controls. Choose every, every-N, range, or specific values for minute, hour, day, month, and weekday. Shows human-readable description and next 10 run times. - [Cron Expression Parser](https://zerotool.dev/tools/cron-parser/): Parse and explain cron expressions in plain English. Preview next 10 scheduled run times. - [Docker Run to Compose](https://zerotool.dev/tools/docker-to-compose/): Convert docker run commands to docker-compose.yml. Supports ports, volumes, env vars, networks, and more. - [Env File Parser](https://zerotool.dev/tools/env-file-parser/): Parse .env files online — visualize key-value pairs, detect errors, and export to JSON. Runs in your browser. - [Gitignore Generator](https://zerotool.dev/tools/gitignore-generator/): Build a .gitignore file from 200+ official github/gitignore templates. Pick languages, frameworks, IDEs, and OS, merge with deduplication, then download or copy. Runs in your browser. - [Timestamp Converter](https://zerotool.dev/tools/timestamp-converter/): Convert Unix timestamps to human-readable dates and vice versa. Auto-detects seconds vs milliseconds. - [Timezone Converter](https://zerotool.dev/tools/timezone-converter/): Convert any time across IANA timezones with automatic DST handling. Compare multiple zones side by side and share results via link. Runs in your browser. ## Other languages - [中文](https://zerotool.dev/zh/llms.txt): Chinese tool names and descriptions; links to /zh/tools/ - [日本語](https://zerotool.dev/ja/llms.txt): Japanese tool names and descriptions; links to /ja/tools/ - [한국어](https://zerotool.dev/ko/llms.txt): Korean tool names and descriptions; links to /ko/tools/ ## Optional - [index.md](https://zerotool.dev/index.md): Site overview and resource index - [categories.md](https://zerotool.dev/categories.md): All tools by category - [about.md](https://zerotool.dev/about.md): Processing, storage, privacy and source code - [Full tool reference](https://zerotool.dev/llms-full.txt): Every tool with its page summary, the "How to Use" steps from its page, and whether it uses the network (English) - [All tools](https://zerotool.dev/tools/): Tool directory with search and category filters - [Blog](https://zerotool.dev/blog/): Guides to the tools and the formats they handle - [About](https://zerotool.dev/about/): What stays on your device, analytics and ads, open source - [Privacy Policy](https://zerotool.dev/privacy/)