Free Online Tools

Fast, simple and privacy-friendly tools that work right in your browser. No installs, no sign-up, no uploads.

All files and data are processed locally on your device.

Popular Tools

The tools people use most.

JSON FormatterFormat, beautify, minify and validate JSON instantly — right in your browser.JSON ValidatorValidate JSON instantly and find syntax errors with the exact line, column and position — right in your browser.Base64 Encoder/DecoderEncode text to Base64 and decode Base64 back to text with full Unicode and emoji support — 100% in your browser.Image CompressorCompress JPG, PNG and WebP images right in your browser. Adjust quality, format and size, download the results — images never leave your device.Word CounterCount words, characters, sentences, paragraphs and lines in real time, with estimated reading time. Works with English, Chinese, Japanese, Korean and any Unicode text — everything stays in your browser.Image ResizerResize images to exact dimensions while keeping aspect ratio — right in your browser.

Browse by Category

Find the right tool for the job.

Developer ToolsFormatters, validators and utilities for developers and data work.Text ToolsCount, analyze and transform text in any language, instantly.ConvertersConvert between formats for data, colors, units and more.CalculatorsEveryday calculators for math, finance, health and more.Image ToolsCompress, resize and convert images without uploading them.Color ToolsPick, convert and generate colors, gradients and palettes for design work.SEO ToolsAnalyze and improve your pages for search engines.Time ToolsTimers, stopwatches and countdown utilities for everyday use.GeneratorsGenerate QR codes, passwords and more in seconds.

Recently Added

Fresh tools, just added.

Color PickerPick any color and copy its HEX, RGB, HSL and HSV values instantly.HEX to RGBConvert HEX color codes to RGB values instantly — free and private.RGB to HEXConvert RGB values to a HEX color code instantly — free and private.Color ConverterConvert between HEX, RGB, HSL, HSV and HWB color formats in any direction.Gradient GeneratorCreate CSS linear and radial gradients visually and copy the CSS code.Contrast CheckerCheck the WCAG contrast ratio between text and background colors instantly.

Why Use ToolStack

Built for speed, simplicity and privacy.

Blazing Fast

Lightweight pages and local processing mean results appear instantly.

Privacy-First

Your data never leaves your browser. Nothing is uploaded or stored.

Free Forever

Every tool is completely free to use, with no sign-up and no limits.

Works Everywhere

Runs on any device and any modern browser — desktop, tablet or phone.

Frequently Asked Questions

Are these tools really free?

Yes. Every tool on ToolStack is free to use, with no account, no subscription and no hidden limits.

Is my data uploaded to a server?

No. Tools like the JSON Formatter process everything locally in your browser — your data never leaves your device.

Do I need to install anything?

No installation is required. All tools run directly in your web browser on any modern device.

Can I use these tools on my phone?

Yes. Every tool is designed mobile-first and works on phones, tablets and desktops.

Which browsers are supported?

All modern browsers are supported, including Chrome, Firefox, Safari and Edge.