Developer Tools

15 tools

Formatters, encoders, hashes and generators for everyday engineering work.

The everyday tools of writing software: formatting something so it can be read, encoding it so it can be transmitted, hashing it so it can be compared, and generating the identifiers and passwords that have to be random. Nothing here needs a login or an install.

If you are debugging, start with the formatter or validator for whatever you are holding — most of the time the answer is that the payload is not the shape you think it is.

JSON Formatter

Format, validate and explore JSON in code, tree, form, text or read-only view.

JSON Compare

Diff two JSON documents — paste them or drop the files — and see exactly what changed.

JWT Decoder

Decode JWT header and payload and inspect expiry claims.

UUID Generator

Generate cryptographically random UUID v4 identifiers in bulk.

Base64 Encoder

Encode text or any file to Base64, with full Unicode support and one-click decoding.

Base64 Decoder

Decode Base64 back to text or to the original file, with encoding in the same tool.

URL Encoder

Percent-encode text for safe use in URLs and query strings.

URL Decoder

Turn percent-encoded URLs back into readable text.

Password Generator

Create strong random passwords with a live strength estimate.

SHA256 Generator

Compute SHA-256 hashes of any text instantly.

Hash Generator

Generate MD5, SHA-1, SHA-256, SHA-384 and SHA-512 hashes of text or a file, in your browser.

Unix Timestamp Converter

Convert Unix epoch seconds to dates and back.

SHA-512 Generator

Generate a SHA-512 hash of any text or file, with a checksum comparison built in.

Markdown Preview

Live Markdown editor with split-view HTML preview and export.

Slug Generator

Turn any title into a clean, SEO-friendly URL slug with a live score.

How these tools work

Every one of these 15 tools runs entirely in your browser. There is no account to create, no file to upload and no daily limit, because the work happens on your own device rather than on a server — which also means there is nothing for us to log, cache or leak. Most of them keep working with the network off once the page has loaded.

Not finding what you need? Press ⌘K to search all 223 tools, or browse the other categories.