Developer Tools, Zero Upload
JSON formatting, epoch conversion, Base64, UUIDs, hashes, cases, slugs — the daily utilities, running entirely in your browser. Paste tokens and payloads without a second thought.
🧰 All tools
- { }JSON Formatter
pretty-print with your preferred indent, get exact error line and column, copy the result.
- ⏱Epoch Converter
Convert Unix timestamps (seconds or milliseconds, auto-detected) to human-readable dates in local time, UTC, and ISO 8601 — and dates back to epoch.
- 🔤Base64 Encode/Decode
Encode text to Base64 and decode Base64 to text, with full Unicode/UTF-8 support — emoji and Chinese included.
- 🔗URL Encode/Decode
spaces, unicode, and special characters to percent-encoding and back.
- 🆔UUID Generator
Generate cryptographically random UUID v4 identifiers — one or up to 100 at once, copy-ready.
- 📄Lorem Ipsum
choose paragraphs and words per paragraph, start with the classic opening, copy in one click.
- 🔠Case Converter
UPPER, lower, Title, Sentence, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, and aLtErNaTiNg.
- #️⃣Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes of any text instantly in your browser.
- 🐌Slug Generator
lowercase, hyphens, accents stripped (Crème → creme).
Why in-browser matters for dev tools
The JSON you paste into a formatter is production data. The string you hash might be a secret; the Base64 you decode might be a JWT. Most online dev tools ship that content to a server — DevNest never does. Every tool here is client-side JavaScript: open the network tab and watch nothing leave, or load a page and go offline. It's also simply faster — no round trip, results as you type.
The lineup covers the daily loop: format and validate JSON with exact error positions, convert epochs with second/millisecond auto-detection, Base64 and URL encoding with proper UTF-8, bulk UUIDs, MD5/SHA hashes with honest security guidance, plus case, slug, and lorem ipsum for the text chores.