Free Developer Tools Online (2026)

66+ browser-based developer tools. Format JSON, decode JWTs, generate UUIDs, test regex, build CSS - all free with no signup.

Why Browser-Based Dev Tools?

Every developer has a handful of utilities they reach for daily: a JSON formatter, a Base64 decoder, a UUID generator. Most of us have bookmarked 5-10 different sites for these.

EaziApps bundles 66+ developer tools in one place, all running client-side. No data leaves your browser, which matters when you're decoding a JWT from production or hashing sensitive values.

Essential Developer Tools

JSON Formatter & Validator

Paste messy JSON, get it formatted with syntax highlighting and validation errors.

Tool: JSON Formatter

  • Auto-detects and highlights syntax errors
  • Collapse/expand nested objects
  • Minify mode for compact output
  • Copy formatted output with one click

JWT Decoder

Decode JWT tokens without sending them to jwt.io (which logs analytics).

Tool: JWT Decoder

  • Decodes header, payload, and signature
  • Shows expiration time in human-readable format
  • Highlights expired tokens
  • No data leaves your browser

Base64 Encoder / Decoder

Encode or decode Base64 strings. Useful for data URIs, API tokens, and debugging.

Tool: Base64 Encoder

UUID Generator

Generate v4 UUIDs for database records, API keys, or test data.

Tool: UUID Generator

  • Generate 1-100 UUIDs at once
  • Copy all with one click

Regex Tester

Test regular expressions against sample text with real-time highlighting.

Tool: Regex Tester

  • Live match highlighting
  • Capture group display
  • Common patterns library

CSS Generators

Save time writing CSS with visual generators:

Tool What it does
Box Shadow Visual shadow builder with multiple layers
Gradient Linear/radial gradient with angle control
Border Radius Per-corner radius with live preview
Glassmorphism Frosted glass effect generator
Flexbox Playground Visual flexbox layout builder
Grid Generator CSS Grid template builder
Clip Path Visual clip-path editor

Encoding & Hashing

Tool Use case
File Hash MD5, SHA-256 checksums
URL Encoder Encode/decode URL strings
HTML Entity Encode special characters
ROT13 Simple cipher for spoilers
Morse Code Text to Morse and back

Formatters & Converters

Tool What it does
SQL Formatter Format SQL queries
CSS Minifier Minify or beautify CSS
HTML Minifier Minify or beautify HTML
JSON to TypeScript Generate TS interfaces from JSON
JSON/CSV Convert between JSON and CSV
JSON/YAML Convert between JSON and YAML
cURL to fetch Convert cURL to JS fetch

Why Client-Side Matters for Developers

The privacy angle is not just marketing when you work with real systems. A JWT from production carries claims about a user. A hash you generate might come from a password or a private file. An API response you format could contain customer data. Tools that upload your input to a server, even to a well-known site, create a copy of that data somewhere you do not control, and some log it for analytics. Client-side tools keep the data in your browser tab, so decoding a token or hashing a value never leaves your machine. For anything touching production or personal data, that difference is the reason to prefer a local tool.

A Sensible Daily Toolkit

You do not need all sixty-six tools every day. Most developers lean on a small core and reach for the rest occasionally. A practical daily set looks like this.

Bookmark the category page rather than each tool, and you have the whole set one click away.

Frequently Asked Questions

Are these tools really free? Yes, all of them run in your browser with no account, no daily limit, and no watermark on output.

Is it safe to decode a production JWT here? The decoder runs client-side, so the token is not sent anywhere. As always, avoid pasting live secrets on any device or network you do not trust.

Do the tools work offline? Once a page has loaded, most of these tools run entirely in the browser and continue to work even if your connection drops.

Can I use the output commercially? Yes. Anything you generate, from formatted code to UUIDs, is yours to use with no restrictions.

Conclusion

One bookmark instead of ten. All 66+ tools run in your browser with zero data transmission. No accounts, no daily limits, no ads interrupting your workflow.

Browse all developer tools at eaziapps.com.