jq Playground

Example: open pull requests by one author

A GitHub REST API list response (shortened) in Input, -r on, and a variable who = octocat:

[{"number":42,"title":"Fix login redirect","draft":false,"user":{"login":"octocat"}},
 {"number":43,"title":"WIP: new parser","draft":true,"user":{"login":"hubot"}},
 {"number":44,"title":"Bump jq to 1.7.1","draft":false,"user":{"login":"octocat"}}]

.[] | select(.draft | not) | select(.user.login == $who) | "#\(.number)\t\(.title)"

Output (2 lines, tab-separated):

#42	Fix login redirect
#44	Bump jq to 1.7.1

The Command line box reads jq -r --arg who octocat '.[] | select(.draft | not) | …' input.json. If you call the API with GitHub CLI instead, note that gh api … --jq does not run jq: it uses gojq, a Go reimplementation, and prints top-level strings raw as if -r were on (go-gh pkg/jq). The gojq README lists the differences: it does not keep object key order, has no -S, -a or --seq, and keeps integer precision in arithmetic where jq does not.

Example: summarise JSON Lines logs

Access logs often have one JSON object per line. With -s (slurp) and -c:

{"ts":"2026-10-01T09:00:01Z","path":"/api/orders","status":200,"ms":42}
{"ts":"2026-10-01T09:00:02Z","path":"/api/orders","status":500,"ms":1203}
{"ts":"2026-10-01T09:00:02Z","path":"/health","status":200,"ms":3}
{"ts":"2026-10-01T09:00:03Z","path":"/api/orders","status":200,"ms":57}

group_by(.path) | map({path: .[0].path, requests: length,
  errors: map(select(.status >= 500)) | length, avg_ms: (map(.ms) | add / length)})

[{"path":"/api/orders","requests":3,"errors":1,"avg_ms":434},{"path":"/health","requests":1,"errors":0,"avg_ms":3}]

-s holds every line in memory. For large files, -n with reduce inputs as $r (…) reads one value at a time; the Options: —arg, -s, -n, -R group in Examples has both forms.

When jq stops with an error

jq prints the values it produced before the error, then the error on stderr, and exits with code 5. The page keeps both:

.items[] | .tags[] on {"items":[{"id":1,"tags":["a"]},{"id":2,"tags":null},{"id":3,"tags":["b","c"]}]} outputs "a", then jq: error (at input.json:1): Cannot iterate over null (null) and exit code 5. The hint below suggests .tags[]? or (.tags // [])[]. For a JSON syntax error, Show in input selects the token jq stopped at; jq reports the position in bytes, and the page converts it so that {"日本":1 x} selects the x. For a filter error, Show in filter selects the reported line.

The page also catches mistakes jq only reports as unexpected INVALID_CHARACTER: curly quotes from a word processor, fullwidth ｜ or ． from an input method, and a filter still wrapped in shell quotes.

Same result as your terminal

Each run is jq FLAGS FILTER input.json, where input.json holds the input plus a final newline. Our test suite runs 71 cases (options, variables, JSON Lines, syntax and runtime errors, halt_error, -e, --seq, --stream) through this page’s engine and through jq 1.7.1, and compares stdout, stderr and the exit code byte for byte. It also runs the 241 examples of the jq 1.7.1 manual; all match except the two that read $PAGER from the environment.

Which jq do you have? Run jq --version. Ubuntu 24.04 (jq 1.7.1-3ubuntu0.24.04), Debian 13 (1.7.1-6) and macOS 27 (/usr/bin/jq prints jq-1.7.1-apple) have 1.7.1. Homebrew has 1.8.2. jq 1.8.0 (NEWS) added trim, ltrim, rtrim, trimstr, toboolean, skip, add/1 and @urid, made ltrimstr error on non-strings and limit error on a negative count, and changed how -1 as $x | … binds. Large integers are kept as written, but arithmetic uses doubles in 1.7.1:

.order_id, .order_id + 0 on {"order_id": 9007199254740993} prints 9007199254740993 and then 9007199254740992.

How it compares (tested 2026-10-02)

We ran the same inputs on three other jq pages in Chromium:

• play.jqlang.org (the jq project’s playground; jqplay.org now redirects there) runs jq 1.8 in the browser: trim works and no request carried our input. It shows output and error together, as here, and stopped repeat(1) with “Operation timed out” after about 30 seconds. Use it when you run jq 1.8.
• jqkungfu.com runs jq.wasm locally. For .[] | .a on [{"a":1},2] it showed 1 without the error; 9007199254740993 came back as 9007199254740992; after a JSON syntax error the previous output stayed on screen.
• jsonwiz.com/jq-online loads jq-wasm@0.3.1 from esm.sh, which answered 404, so every run showed “Failed to fetch dynamically imported module”.

Limits

• No files besides the input: --slurpfile, --rawfile, -f, -L, import and include are not available; --args / --jsonargs are left out.
• $ENV and env show the WebAssembly runtime’s fixed environment (HOME=/home/web_user), not yours. now and the local-time functions use your browser’s clock.
• Inputs over 2 MB run only when you press Run; files over 2 MB are not shown in the editor. Output over 1 MB is cut in the panel (Copy and Download are complete).
• A filter is stopped after 10 seconds plus 1 second per MB of input. A run that exhausts memory or recurses too deep restarts the engine.
• Colour (-C) is ignored; output is not colourised.

Related tools: JSONPath Tester for path queries, JSON Formatter to pretty-print, JSONL Converter between JSON arrays and JSON Lines, JSON Diff to compare two outputs.