Format guide
What is JSON?
JavaScript Object Notation is a lightweight text format for structured data (objects, arrays, strings, numbers, booleans, null), created by Douglas Crockford / ECMA (2001). JSON is the default payload for web APIs and many app configs. It maps cleanly to programming types. Convert JSON to CSV when analysts need a flat table, or to YAML when humans must edit the same data as config.
JSON format specifications
- Full name
- JavaScript Object Notation
- Kind
- structured data
- File extension
- .json
- MIME type
- application/json
- Developer / standard
- Douglas Crockford / ECMA · 2001
- Compression
- none or container
- Quality model
- Lossless / not lossy
- Container
- No / single bitstream typical
- Common codecs
- —
- Technical sources
- —
- Transparency
- Not supported
- Animation
- No (still / non-animated typical use)
- Typical size
- Compact; pretty-print increases size for readability
- Browser support
- Native JSON.parse / fetch; not a document viewer format
- Compatibility
- Native in JavaScript; first-class libraries in every major language
JSON compression & quality
JSON compression: none or container. Lossless (or non-destructive packaging) keeps reconstructable data — size savings come from packing efficiency, not throwing detail away. Typical size profile: Compact; pretty-print increases size for readability. Quality note: Exact for supported literal types; no native date type
Quality: Exact for supported literal types; no native date type
Typical size: Compact; pretty-print increases size for readability
Transparency & animation
JSON does not support an alpha channel. Convert to PNG, WebP, AVIF, or SVG when you need transparent backgrounds.
JSON is a still-media or non-animated format in typical use. Use GIF, APNG, video, or animated WebP when you need motion.
JSON metadata
Usually none beyond encoding/BOM — structure is the content. Comments allowed in YAML/TOML.
Best use cases for JSON
- REST API bodies
- App configuration (package.json and friends)
- NoSQL document exports
- Interchange between services
- Browser and Node tooling
When to avoid JSON
- End-user spreadsheets without conversion
- Documents with comments (use JSONC/YAML elsewhere)
- Large binary assets (use files + URLs)
- Hand-editing huge deeply nested trees
Advantages
- Ubiquitous
- Strict grammar
- Nested structures CSV cannot express
- Easy to validate
- Great tooling
Disadvantages
- No comments in strict JSON
- Easy to break with trailing commas
- Unfriendly for non-developers
- Schema is optional unless you add one
Compatibility
Native in JavaScript; first-class libraries in every major language
Browsers: Native JSON.parse / fetch; not a document viewer format
Software support
- Browsers / DevTools
- VS Code
- jq
- Postman
- Format Convertly
Device support
- Developer workstations and servers
- Modern desktops
- Phones and tablets with compatible apps
How to open JSON
Pretty-print in an editor or browser DevTools. Validate before shipping to production APIs.
How to convert JSON
Use Format Convertly to convert JSON↔CSV or JSON↔YAML in your browser when the next tool in your pipeline needs a different shape.
Popular JSON conversions
Convert to JSON
Incoming conversions strengthen the JSON cluster — e.g. JPG → JSON, PNG → JSON.
JSON comparison guides
Compare JSON with related formats to pick the right container for quality, size, and compatibility.
Best format guides featuring JSON
Decision pages that cite JSON — the next hop after a vs comparison.
JSON how-to guides
Related formats
JSON tools
Tools extend the format graph beyond one-off conversion — compression, metadata, and utilities for real workflows.
Technical sources
JSON FAQ
What is a JSON file?
JSON is a lightweight text format for structured data (objects, arrays, strings, numbers, booleans, null). JSON is the default payload for web APIs and many app configs. It maps cleanly to programming types. Convert JSON to CSV when analysts need a flat table, or to YAML when humans must edit the same data as config.
Is JSON lossy or lossless?
JSON is typically lossless or non-destructive in common use (none or container).
Does JSON support transparency?
JSON does not support an alpha channel. Convert to PNG, WebP, AVIF, or SVG when you need transparent backgrounds.
How do I open a JSON file?
Pretty-print in an editor or browser DevTools. Validate before shipping to production APIs.
How do I convert JSON privately?
Use Format Convertly to convert JSON↔CSV or JSON↔YAML in your browser when the next tool in your pipeline needs a different shape. Format Convertly keeps processing in your browser so files are not uploaded to a conversion server.
Can JSON include comments?
Strict JSON cannot. Use JSONC in tooling that allows it, or YAML/TOML when humans must annotate configs.
Are my JSON files uploaded on Format Convertly?
No. JSON conversion runs in your browser. Files are not sent to Format Convertly servers for processing.