Format, convert, encode, validate — all in your browser. No server. No tracking.
Private by default
Your data never leaves your device. No logs, no uploads, ever.
Instant results
Every tool processes your input instantly, with zero delays or loading spinners.
Always free
No account, no rate limits, no paywalls. Open to everyone.
JSON Formatter
Beautify and format JSON with customizable indentation. Instantly readable, syntax-highlighted output.
JSON Validator
Validate JSON syntax and get clear error messages with line numbers to quickly fix issues.
Base64 Encode
Encode text or files to Base64. Used for embedding binary data in text-based formats.
JWT Decoder
Decode JWT tokens and inspect the header, payload, and signature without any verification.
Password Generator
Generate strong, random passwords with configurable length, character sets, and rules.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from any text using Web Crypto APIs.
Regex Tester
Test regular expressions with live match highlighting, group capture, and flag controls.
Cron Expression Generator
Build, explain, and preview cron expressions with next run times.
DevTools is a free collection of 130+ utilities built for developers, designers, and technical users. Every tool is instant, completely private, and requires no account or installation — just open and use.
DevTools is built for software engineers, backend developers, frontend developers, DevOps engineers, QA testers, and anyone who works with data formats, APIs, or web technologies daily. Whether you need to quickly decode a JWT token, validate a large JSON payload, generate a secure password, or test a regular expression, DevTools has a dedicated tool for it — no installation, no setup, just open and use.
The collection spans 12 categories: format and validate JSON; encode or decode Base64, URL, HTML, and JWT; process text with diff, sort, and case conversion; convert between CSV, XML, YAML, and SQL; generate passwords, hashes, UUIDs, and RSA key pairs; parse HTTP headers and status codes; test and explain regular expressions; work with Unix timestamps and timezones; generate CSS gradients and shadows; perform math conversions; calculate subnets; and dozens of miscellaneous utilities like QR code generation, cron expression building, and gitignore file creation.
Privacy is built into how DevTools works, not bolted on afterward. When you paste a private API key, a confidential document, or sensitive credentials into any tool, that data stays on your device and is never transmitted anywhere. Your input disappears the moment you close the tab.
Common questions: Is it free? Yes, always. Does it store my data? No — all processing happens locally in your tab. Does it work offline? Yes, once the page loads most tools work without a connection.