Dev Tools
Free Developer Tools, Private and In-Browser
Twelve free developer tools: JSON formatter and diff, Markdown preview, JWT decoder, Base64, hashes, UUIDs, timestamps and an SEO checker. Free, no sign-up.
These tools run entirely in your browser, so they need JavaScript enabled. Nothing you paste is uploaded either way.
Work with JSON
- JSON Formatter Pretty-print and validate
- JSON Compare Spot what changed
Write & compare text
- Markdown Preview Live preview as you type
- Text Compare Line-by-line comparison
Encode & decode
- Base64 Encode and decode
- URL Encode Percent-encode and inspect
- JWT Decoder Read a token's claims
Generate & convert
- HTML to PDF Render and save as PDF
- Hash Generator SHA-1 through SHA-512
- UUID Generator Random v4 identifiers
- Timestamp Converter Epoch, ISO and local time
Inspect & audit
- SEO Details Fetcher Audit a page's SEO
All tools