Free Online Developer Tools

Essential utilities for developers and engineers. Encode and decode Base64, inspect JWT tokens, format and validate JSON, test regular expressions, encode URLs, and generate cryptographic hashes — all client-side, all free.

Base64 Encoder / Decoder Encode and decode text or files using Base64 encoding.
JWT Decoder Decode and inspect JSON Web Token header, payload, and signature.
JSON Formatter Format, validate, and minify JSON with syntax highlighting.
Regex Tester Test and debug regular expressions with live match highlighting.
URL Encoder / Decoder Encode and decode URLs and query strings using percent-encoding.
Hash Generator Generate SHA-1, SHA-256, and SHA-512 cryptographic hashes for any text.
CSS Minifier Minify CSS to shrink file size — strips comments and whitespace, shows the savings.
HTML Formatter Beautify or minify HTML with clean indentation — paste messy markup, get readable code.

Why Use Online Developer Tools?

Developer tools eliminate the need to write one-off scripts or open a terminal for quick encoding and decoding tasks. When you are debugging an API, inspecting a JWT token, or checking a hash value, having instant browser-based tools saves significant time. Our tools run entirely client-side — your data never leaves your browser.

Common Developer Workflows

API Debugging

Use Base64 to encode Basic Auth credentials for test requests. Use JWT Decoder to inspect token claims and check expiration without a library. Use URL Encoder to prepare query strings.

Data Processing

Use JSON Formatter to make API responses readable. Use Hash Generator to verify file checksums, create test signatures, or check if values match expected hashes.

Security and Auth

Use JWT Decoder to understand token structure and debug authentication issues. Use Hash Generator to test SHA-256 and SHA-512 hashes for integrity checks. All processing is local — never send tokens to external tools.

Pattern Matching

Use Regex Tester to build and validate regular expressions with live feedback. Test email validation patterns, URL parsing, date formats, and complex data extraction patterns before putting them in production code.

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Frequently Asked Questions

Are these developer tools safe for sensitive data like tokens?

Yes. Every tool runs entirely in your browser — JWTs, hashes, and encoded data are never transmitted to a server. Decoding a token or hashing a value happens locally, so nothing sensitive leaves your machine.

Do I need to install anything or sign up?

No. All developer tools work instantly in any browser with no installation, no account, and no usage limits. They are an alternative to writing throwaway scripts or opening a terminal.

Can I use these tools offline?

Once a tool page has loaded, the processing is client-side JavaScript, so it keeps working even if your connection drops. The first load requires a connection to fetch the page.

Which hash should I use, MD5 or SHA-256?

Use SHA-256 for anything security-related — MD5 is cryptographically broken and only suitable for non-security checksums. For password storage, use a dedicated algorithm like bcrypt or Argon2 rather than a raw hash.