31+ Free Tools · Privacy-First · No Signup

Tiny tools.
Big productivity.

A growing collection of tools for developers, writers, and creators. Fast, private, and free. Everything runs in your browser, so nothing gets uploaded, tracked, or stored.

100% Client-SideNo Sign UpZero TrackingOpen Source Ideas
31+
Free Tools
0
Data Collected
Forever Free
Text & Writing
5 tools
Image & File
6 tools
Developer
15 tools
🔥 Popular

JSON Formatter

Format, beautify, minify, and validate JSON data instantly.

Open Tool

Base64 Encoder/Decoder

Encode text to Base64 or decode Base64 strings back to plain text.

Open Tool
✨ New

URL Encoder/Decoder

Encode or decode URLs and query parameters. Handle special characters safely.

Open Tool
✨ New

Color Converter

Convert colors between HEX, RGB, and HSL formats. Pick colors visually.

Open Tool
✨ New

Regex Tester

Test and debug regular expressions with real-time matching, highlighting, and group extraction.

Open Tool

CSS Minifier

Minify CSS code to reduce file size. Remove comments, whitespace, and unnecessary characters.

Open Tool

HTML Minifier

Minify HTML by removing comments, whitespace, and unnecessary tags.

Open Tool
✨ New

Timestamp Converter

Convert Unix timestamps to human-readable dates and vice versa. Multiple format outputs.

Open Tool
✨ New

QR Code Generator

Generate QR codes for URLs, text, WiFi, and more. Download as PNG.

Open Tool

Markdown to HTML

Convert Markdown text to clean HTML. Live preview and copy-ready HTML output.

Open Tool
✨ New

JWT Decoder

Decode and inspect JSON Web Tokens. View header, payload, and signature instantly.

Open Tool
✨ New

UUID Generator

Generate random UUIDs (v4), timestamp UUIDs (v7), or bulk lists. Copy-ready output.

Open Tool
✨ New

YAML ↔ JSON Converter

Convert between YAML and JSON formats. Instant, validated, bidirectional.

Open Tool
✨ New

Text Diff Checker

Compare two blocks of text side-by-side. See additions, removals, and changes highlighted.

Open Tool
✨ New

CSS Gradient Generator

Design beautiful linear and radial CSS gradients with live preview. Copy-ready code.

Open Tool
SEO
3 tools
Security
2 tools

Why 3STF Tools

Tools that respect your time and privacy.

Most online tools are slow, covered in ads, behind signup walls, or secretly collecting your data. We built 3STF Tools for one simple reason: tools should just work. Every tool runs entirely in your browser. Your text, images, and passwords never leave your device.

Lightning Fast

Static-rendered pages, instant interactions. No waiting for servers.

Truly Private

Zero data leaves your browser. Works offline after first visit.

Always Free

No paywalls, no premium tiers, no surprise features locked away.