Best Free Tools Every Developer Should Bookmark

Every developer accumulates a personal toolkit of small utilities for tasks that come up too often to solve from scratch each time, but aren't worth installing dedicated software for. Here are five browser-based tools worth bookmarking, and what each one is actually good for.

JSON Formatter

API responses and config files are often minified into a single unreadable line, or broken by a stray comma or missing quote. A JSON Formatter pretty-prints JSON with proper indentation and syntax highlighting, and — more usefully — flags exactly where invalid JSON fails to parse. That second part matters more than the formatting itself: eyeballing a 200-line minified payload for a missing comma is slow, and a parser error pointing at the exact character is usually the fastest way to fix it.

Color Picker & Gradient Generator

Translating a design handoff into CSS means converting between HEX, RGB, and HSL more often than seems reasonable. A Color Picker & Gradient Generator converts between all three formats live, and builds gradients you can copy as ready-to-use CSS instead of guessing at angle and color-stop values by hand.

QR Code Generator

QR codes come up for more than restaurant menus — event check-ins, linking a printed document to its latest online version, or dropping a portfolio link on a business card. A QR Code Generator turns any URL or text into a downloadable PNG in seconds, which beats reaching for a design tool just to generate one code.

Hash Generator

Verifying file integrity, generating a quick fingerprint for cache-busting, or checking that two pieces of text are byte-identical are all jobs for a hash function, not a diff tool. A Hash Generator produces MD5, SHA-1, and SHA-256 hashes from any text as you type — useful for spot-checking a downloaded file's checksum or generating a stable key from a string without writing a script for it.

Base64 Encoder / Decoder

APIs that accept file uploads as a JSON field, email attachments encoded inline, and data URIs embedded directly in CSS all rely on Base64. A Base64 Encoder / Decoder encodes text or files to Base64, or decodes a Base64 string back to readable text or a downloadable file — handy for inspecting what's actually inside a token or payload before you trust it.

Why browser-based tools are worth the bookmark

None of these require an account, a subscription, or a software install — they run entirely client-side, so nothing you paste or upload is ever sent to a server. For quick, one-off tasks that come up mid-debugging or mid-deploy, that's a meaningfully faster loop than opening a desktop app or writing a five-line script you'll throw away right after.

Explore more

These five cover a lot of ground, but they're a small slice of what's available. Browse the All Tools page for the full library, including formatters, converters, and generators for nearly every everyday development task.