19 tools · Free · No sign-up · Client-side

Developer Utilities

Fast, free, and privacy-friendly tools for everyday development. All processing happens in your browser — your data never leaves your device.

HTTP & APIs

1 tool
{}

JSON & Data

3 tools
🔐

Encoding & Security

4 tools

Generators

3 tools
✍️

Text & Writing

2 tools
.*

Regex & Scheduling

3 tools
🎨

Design & Color

1 tool
🖼️

Image Tools

2 tools

Free online developer tools that respect your privacy

DevUtilities.dev is a collection of 19 focused utilities that developers use every day. All tools run entirely in your browser — no sign-up, no pop-ups, no paywalls. The site has no tracking analytics for input, no server-side logging of payloads, and no third-party uploads. The only network traffic from a tool page is to load the page itself.

JSON, YAML and configuration

The JSON Formatter validates, beautifies and minifies JSON; the JSON Diff compares two documents path-by-path; the YAML ↔ JSON Converter handles Kubernetes manifests, Docker Compose and GitHub Actions workflows. Together they cover almost every configuration- and API-debugging task that comes up in a working day.

Authentication, encoding and hashing

The JWT Decoder parses headers and claims and verifies HS256/RS256 signatures locally using the Web Crypto API. The Base64 and URL Encoder handle every percent-encoding and Base64 variation you will run into in HTTP work. The Hash Generator computes MD5, SHA-1, SHA-256 and SHA-512 for text or files of any size.

Regex, cron and other expressions

The Regex Tester evaluates JavaScript-flavour regex against sample text with highlighted matches; the Regex Builder composes patterns visually; the Cron Builder assembles cron expressions and shows upcoming run times in your local timezone.

Your data stays in your browser

Every tool processes input locally with standard browser APIs — JSON.parse, crypto.subtle, Canvas. Tokens, JSON payloads, images and files are never uploaded. You can confirm this by opening your browser's network panel and pressing a tool's action button — no outbound request is made.

Developer guides

For deeper background on the concepts behind the tools, read our long-form developer guides — original articles on JSON, JWT, regex and cron written by working engineers. Each guide focuses on the specific pitfalls that turn into bug tickets if you ignore them.