JSON Formatter
Format, validate, minify and explore JSON with precise error locations. Runs locally.
Developer
5 toolsFree · private · no sign-up
Developer tools
Fast, private utilities for everyday coding. Format and validate JSON, encode and decode Base64, URLs and JWTs, generate hashes and UUIDs, and create realistic mock data.
New
Base64 & URL Encoder
Encode and decode Base64, URL, HTML entities and inspect JWT tokens. Unicode-safe and private.
Developer
New
Hash Generator
MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes of text or files, plus HMAC signing.
Developer
New
UUID Generator
Generate UUID v4 and time-ordered v7 identifiers in bulk, validate UUIDs and copy in one click.
Developer
Mock Data Generator
Generate realistic test data from a custom schema and export it as JSON or CSV.
Developer
About our developer tools
Because everything runs in your browser, it's safe to paste API responses, tokens and config files. Nothing is logged or uploaded. The JSON formatter pinpoints syntax errors to the exact line and column, and the hash generator uses the Web Crypto API for SHA digests and HMAC.
Need identifiers? The UUID generator produces random v4 and time-ordered v7 UUIDs in bulk, and the mock data generator exports seed data as JSON or CSV.
All developer tools
- JSON Formatter: Format, validate, minify and explore JSON with precise error locations. Runs locally.
- Base64 & URL Encoder: Encode and decode Base64, URL, HTML entities and inspect JWT tokens. Unicode-safe and private.
- Hash Generator: MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes of text or files, plus HMAC signing.
- UUID Generator: Generate UUID v4 and time-ordered v7 identifiers in bulk, validate UUIDs and copy in one click.
- Mock Data Generator: Generate realistic test data from a custom schema and export it as JSON or CSV.
Frequently asked questions
Is it safe to paste secrets or tokens?
Yes. These tools don't send your input anywhere; processing happens in JavaScript on your device. You can even disconnect from the internet and they keep working.
What's the difference between UUID v4 and v7?
UUID v4 is fully random. UUID v7 starts with a millisecond timestamp, so values sort by creation time, which makes them friendlier as database primary keys.
Does the Base64 encoder support emoji and non-Latin text?
Yes. Text is encoded as UTF-8 before Base64 encoding, so emoji, Arabic, Chinese and other scripts round-trip correctly.
Explore other categories
All 41 toolsFinance tools
Calculators for money, loans, savings and markets.
8 toolsHealth tools
BMI, nutrition and lifetime body stats.
6 toolsProductivity tools
Timers, calculators, converters and writing tools.
9 toolsDesign tools
Colors, images and QR codes.
3 toolsSecurity tools
Passwords, strength checks and private messages.
3 toolsLifestyle tools
Age, travel, personality, sport and fun.
7 tools