20 Free Online Tools Every Developer Should Bookmark

派大星 — Thu, 02 Apr 2026 04:33:30 +0000

As developers, we constantly reach for small utilities — formatting JSON, testing regex, converting timestamps, encoding Base64. Most of us end up on ad-heavy sites that are slow and clunky.

I built AItinytools.com — a collection of 20+ free, fast, browser-based tools. No sign-up, no ads wall, and most processing happens locally in your browser (your data never leaves your machine).

Here's the full list:

🔐 Security & Encryption

MD5 Hash Generator — Generate MD5 hashes for strings and files. Supports 32-bit, 16-bit and Base64 output.
SSL Certificate Decoder — Analyze any SSL/TLS certificate: issuer, validity, public key, SAN domains and full chain.

🛠 Developer Tools

JSON Formatter — Beautify, minify and validate JSON. 2-space, 4-space or tab indentation. Shows key counts and file size.
SQL Formatter — Format and beautify SQL queries with syntax highlighting. MySQL & PostgreSQL supported.
Regex Tester — Live match highlighting, capture groups, replace mode. Supports g, i, m, s flags.
chmod Calculator — Convert between symbolic (rwxr-xr-x) and numeric (755) permissions with interactive checkboxes.

🔄 Data & Format Converters

YAML / JSON / TOML Converter — Paste any format, instantly convert to the others with syntax validation.
Base64 Encoder & Decoder — Encode/decode text and files. URL-safe Base64 supported.
URL Encoder & Decoder — Percent-encoding and decoding with encodeURIComponent and full encoding modes.
Number Base Converter — Binary, octal, decimal, hex and any custom base (2–36).
Unix Timestamp Converter — Timestamps to dates and back. Live current timestamp with timezone support.

📝 Text & Code

Text Diff — Compare two texts with line-by-line diffs, side-by-side or unified view.

🌐 Network & Hardware

Subnet Calculator — Network address, broadcast, host range and wildcard mask from any IP/CIDR.
CPU Benchmark Chart — Latest Intel vs AMD processor comparisons for gaming and workstations.
GPU Benchmark Chart — GeForce RTX, Radeon RX, Intel Arc performance rankings.

🖼 Image Tools

Image Compressor — Compress JPEG, PNG, WebP in browser. No upload, 100% private.
QR Code Generator — Text or URL to QR code. Customize size, error correction and colors.

🌍 Translation & More

AI Translator — AI-powered translation for 100+ languages with natural-sounding results.
Unit Converter — Length, mass, temperature, area, volume, speed, time, data, pressure, energy, power and angle.
NZ Driving Test — 500 questions with detailed explanations and multilingual support.

All tools are free and work on desktop and mobile. If you find them useful, check out the full list on GitHub: awesome-free-online-tools.

What tools do you use daily? Would love to hear suggestions for new ones to build!

DEV Community: 派大星