Developer Tools
JSON, Base64, URL encoding, hashes, UUID, JWT, and HTTP status code & file extension references — every tool in one place, free and account-free.
JSON Formatter
Format, validate, and minify JSON — with error highlighting and pretty-printed indentation.
Base64 Encode / Decode
Encode text to Base64 or decode it back — with UTF-8 support and a URL-safe variant.
URL Encode / Decode
Percent-encode and decode URLs and query parameters — for safe links and requests.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text — entirely in the browser.
UUID Generator
Generate random UUIDs (v4) — one at a time or in batches, with one-click copy.
JWT Decoder
Decode a JSON Web Token’s header and payload — readable, without sending the token (no signature verification).
Regex Tester
Test regular expressions live — match highlighting, capture groups, every flag and a replace mode.
Cron Explainer
Understand a cron expression in plain language — with a field breakdown and the next run times.
HTTP Status Codes
Reference for every HTTP status code — meaning, when it is used, and a dedicated page per code.
File Extensions
What a given file extension is, which program opens it, and what format it is — a page for each.
Unix Timestamp Converter
Live current Unix timestamp and timestamp ↔ date conversion — seconds, milliseconds, micro- and nanoseconds.
Subnet Calculator (CIDR)
Network and broadcast address, masks, and host counts for any IPv4 block — with a page for every /0–/32 prefix.
Number Base Converter
Binary, octal, decimal, hexadecimal, and any base 2–36 — with huge-number (BigInt) support.
Frequently asked questions
Are the developer tools free?
Yes. Every tool — JSON formatter, Base64 and URL encoding, hash and UUID generators, JWT decoder, and the reference pages — is completely free and works without an account.
Is my data sent to a server?
No. Formatting, encoding, hashing, UUID generation, and JWT decoding all run entirely in your browser. Nothing you enter is sent or stored.
Does the JWT decoder verify the signature?
No. It decodes and displays the header and payload in a readable form but does not validate the signature — so it is safe to use without revealing your secret key.
Which hashing algorithms are supported?
The hash generator supports MD5, SHA-1, SHA-256, and SHA-512, computed locally via the browser’s Web Crypto API.
What are the HTTP status code and file extension pages?
They are references with a dedicated indexed page for each HTTP status code (e.g. 404, 500) and each popular file extension — with an explanation, context, and FAQs.