Free Online Developer Tools

Every developer keeps a mental drawer of small utilities — format some JSON, decode a Base64 string, generate a UUID, hash some text, inspect a JWT, test a regex, convert a timestamp. Reaching for a random website for each one is slow and, for anything sensitive, risky. This cluster gathers the essentials as fast, private, in-browser tools, and this guide is the reference for when and why to use each.

All developer tools

Password GeneratorCreate strong, random passwords with a strength meter.JSON FormatterBeautify, minify, and validate JSON instantly.Base64 Encode / DecodeEncode and decode Base64 text, with full Unicode.URL Encoder / DecoderPercent-encode and decode URLs safely.UUID GeneratorGenerate secure v4 UUIDs in bulk.Hash GeneratorSHA-1, SHA-256, SHA-384 & SHA-512 from text.JWT DecoderInspect the header and payload of a JWT.Regex TesterTest regular expressions against live text.Timestamp ConverterUnix epoch to human dates, and back.

Guides & tutorials

6 min read

URL Encoder and Decoder: Encoding Explained

What %20 and %2F actually mean, when you need to encode a URL, and how to encode or decode query strings correctly — with the component vs full-URL distinction.

5 min read

What Is a UUID? (And How to Generate One Safely)

UUIDs are the unique IDs behind modern software. Learn what they are, why v4 is the one you usually want, and how to generate them securely in bulk.

5 min read

How to Generate a Hash (SHA-256 and Friends), Explained

What a hash is, why SHA-256 is everywhere, why MD5 is dead, and how to generate a hash from text in your browser for checksums and fingerprints.

Frequently asked questions

Are developer inputs sent to a server?

The developer utilities are designed to run in your browser for quick, private inspection and generation.

Can I decode a JWT with these tools?

Yes. JWT Decoder displays the header and payload for inspection; it does not verify signatures.

Which tool formats JSON?

JSON Formatter prettifies and validates JSON so nested data is easier to read.