Developer · JSONLint
Validate and format JSON
Check JSON syntax and reformat a data payload.
Open JSONLintWorkflow guide
Validate, compare and debug JSON before sending an API request
Use a validator for syntax, a diff for changes and a transformation tool for encoding issues.
Validate first
Check the JSON before investigating the network. Common problems include unquoted property names, extra commas, invalid escapes and mismatched brackets.
Compare and transform
A text diff can reveal a renamed field or changed value between two payloads. CyberChef is useful for inspecting encoded values; Base64 is encoding, not encryption.
Keep credentials private
Replace access tokens, passwords and real customer values with synthetic examples. A shared URL or browser history can retain input, even where processing is local.
Compare the options
| Tool | Best for | Cost / account | Processing |
|---|---|---|---|
| Validate and format JSON | Check JSON syntax and reformat a data payload. | free · No signup reported | Processing unverified |
| Compare text | Highlight differences between two versions of text or code. | free tier · No signup reported | Processing unverified |
| Encode, decode and transform data | Chain operations such as Base64, hexadecimal conversion and data transforms. | free · No signup reported | Provider says local |
| Preview HTML, CSS and JavaScript | Experiment with browser code and preview the output. | free · Signup unverified | Processing unverified |
Tools to explore
Writing · Diffchecker
Compare text
Highlight differences between two versions of text or code.
Open DiffcheckerDeveloper · CyberChef
Encode, decode and transform data
Chain operations such as Base64, hexadecimal conversion and data transforms.
Open CyberChefDeveloper · MDN
Preview HTML, CSS and JavaScript
Experiment with browser code and preview the output.
Open MDNRecommendations are based on public provider information, not comparative performance testing.