jq Playground
Run jq filter expressions against JSON directly in your browser. Pipes, map, select, slices, string interpolation — no install, no server, fully private.
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What is jq Playground?
jq Playground is an in-browser environment for testing jq filter expressions against your own JSON. It implements a focused subset of the jq language — pipes, field access, iteration, map, select, string interpolation and more — in pure JavaScript, so there is nothing to install and no data ever leaves your machine.
Key Benefits
- Test jq filters instantly without installing jq locally
- Privacy-first: JSON is processed entirely in your browser
- Learn jq faster with preset example filters
- Clear error messages pinpoint syntax problems
- Copy or download results as formatted text
Common Use Cases
- •Prototyping a jq filter before adding it to a shell pipeline
- •Learning the jq language with live feedback
- •Debugging why an existing jq filter returns unexpected output
- •Extracting and reshaping fields from API JSON responses
- •Teaching teammates jq during pair-programming sessions
How to Use jq Playground
- Paste your JSON: Paste any JSON document into the input box, or leave it empty to use the built-in sample data.
- Type a jq filter: Write a jq expression such as .users[] | .name in the filter field. Results update as you type.
- Try a preset: Click one of the preset chips below the filter box to load common patterns like map, select, or string interpolation.
- Copy or download: Review the formatted output — one result per line — then copy it to your clipboard or download it as a text file.
Key Features
- Full jq subset: field access, iteration, pipes, comma streams, and slices
- Built-in functions: length, keys, values, map, select, sort, unique, add, min, max
- String interpolation with (...) syntax for templated output
- Alternative operator (//), comparisons, arithmetic, and if/then/else control flow
- One result per line with copy and download options
- Runs entirely in-browser — your JSON never leaves your machine
Frequently Asked Questions
Does this tool send my JSON to a server?
No. The jq engine is implemented in JavaScript and runs entirely in your browser. Your JSON and filters never leave your machine.
Which jq features are supported?
Field access, array indexing and slicing, iteration (.[]), recursive descent (..), pipes, comma streams, the alternative operator (//), arithmetic and comparisons, if/then/else, object and array construction, string interpolation, and common built-ins like length, keys, map, select, sort, unique, add, min, and max.
Why does my filter show a query error?
The engine reports the first syntax or type error it hits. Common causes are a missing end keyword for if, using a function that is not in the supported set, or applying an arithmetic operator to non-numeric values.
Can I use variables or define functions?
User-defined functions and variable bindings (as bindings with $names) are not supported in this subset. Stick to filters composed from the supported features listed above.