Developer Tools Online
Inspect JSON and JWTs, convert data to CSV, test regex patterns, encode text, generate identifiers and debug Unix timestamps.
9 tools for this category
JSON to CSV Converter
Convert JSON objects to downloadable CSV with combined headers and spreadsheet formula protection.
Open tool →JWT Decoder
Decode, read, and inspect JSON Web Token header, payload claims, and signature info.
Open tool →JSON Formatter
Prettify, validate, format, and minify JSON strings with live error highlighting.
Open tool →Base64 Encoder / Decoder
Encode plain text into Base64 formats or decode Base64 back into readable text.
Open tool →Regex Tester
Test and debug Regular Expressions with real-time match highlighting, group extraction, and replace engine.
Open tool →UUID / ULID Generator
Generate UUID v4, v1, v5, and lexicographically sortable ULIDs in bulk with custom quote formatting.
Open tool →Timestamp Converter
Convert Unix epoch timestamps to human-readable dates (UTC/Local/ISO) and convert dates back to timestamps.
Open tool →Hash Generator
Generate cryptographic SHA-256, SHA-512, SHA-1, and MD5 hashes for text, secret HMAC keys, and file checksums.
Open tool →HTML Live Preview
Live isolated HTML, CSS, and JS editor with real-time preview, device viewport switcher, and component templates.
Open tool →Build a workflow around the result
Use synthetic API data to reproduce a problem. Validate JSON before converting to CSV, confirm timestamp units before reading date claims, and inspect signatures separately from token decoding. Match regex syntax to the engine used by your application. Test copied output in the actual system; readable output does not validate business rules or establish trust. Check encoding and line endings when comparing hashes or moving data between tools.
Related practical guides
- Convert JSON to CSV: Headers, Nested Values and Spreadsheet Pitfalls
- How to Decode and Read JWT Tokens Without Confusing Decoding with Verification
- How to Validate and Format JSON with Eleventor
- Convert Unix Timestamps to Readable Dates: Seconds, Milliseconds and UTC
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