Fast, free utilities for everyday dev tasks. Everything runs in your browser — nothing leaves your machine.
Every tool on this site runs entirely in your browser. When you paste a JWT token, an API key, or a database export — it never touches a server. Not ours, not anyone's. The processing happens locally using your browser's JavaScript engine. You can disconnect from the internet after loading the page and every tool will still work.
These are the tools we reach for every day — formatting an API response, decoding a JWT to debug an auth issue, generating a UUID for a database migration, testing a regex before adding it to production code. No accounts, no rate limits, no paywalls. Just open the tool and use it.
ByteUtilities is and will always be free. There are no premium tiers, no feature locks, and no signup required. We keep the lights on with unobtrusive advertising. Every tool works at full capacity for every visitor, whether it's your first visit or your hundredth.
The JSON Formatter is the most-used tool on this site. Developers paste minified API responses, config files, and database exports to make them readable. It validates syntax in real time, highlights errors with exact line numbers, and supports 2-space, 4-space, and tab indentation.
The JWT Decoder is invaluable when debugging authentication. Paste any JSON Web Token and instantly see the header algorithm, all payload claims, expiry countdown, and verify HMAC signatures against your secret — without sending the token to a third-party server.
The Regex Tester provides live match highlighting as you type, supports all four JavaScript flags (g, i, m, s), shows capture groups with their indices, and includes 12 quick-start patterns for common tasks like email validation, URL matching, and date parsing.
The Hash Generator supports MD5, SHA-1, SHA-256, SHA-384, and SHA-512 with both hex and Base64 output. All hashing uses the browser's native Web Crypto API — the same cryptographic implementation used by your browser for HTTPS.
The Password Generator uses crypto.getRandomValues() — cryptographically secure randomness — to generate passwords. Not Math.random(), which is predictable. Every password is genuinely random and never transmitted anywhere.
The Diff Checker uses a Longest Common Subsequence algorithm — the same approach as Git — to compare two texts line by line and highlight exactly what changed. Useful for comparing config files, API responses, and document versions.
Are these tools really free?
Yes, completely free. No signup, no account, no premium tier. All 12 tools work at full capacity for every visitor. We display unobtrusive ads to cover hosting costs.
Is my data safe?
Yes. Every tool processes data locally in your browser. Nothing is sent to our servers or any third-party server. Safe for sensitive data including API keys, passwords, JWT tokens, and private documents.
Do the tools work offline?
Once a page is loaded, all tools work without an internet connection. The processing is entirely client-side JavaScript — no server requests are made when you use a tool.
What programming languages are supported?
The Regex Tester uses the JavaScript regex engine. JSON tools follow the JSON specification (RFC 8259) which is language-agnostic. Hash generation uses standard algorithms (SHA-2 family) that produce identical results across all languages.
How do I report a bug or request a tool?
Visit our About page for contact information. We actively maintain all tools and respond to bug reports.
Are more tools being added?
Yes. We're actively building new tools based on what developers need most. Upcoming tools include XML to JSON Converter, JSON to Table viewer, and more encoding utilities.