About useonlinetools

Why this exists

Most online tool websites ask you to upload your files to their servers before doing anything with them. That means your PDFs, images, and data pass through someone else's infrastructure — often without transparency about what happens to those files afterward.

useonlinetools takes a different approach. Every tool runs entirely in your browser. When you merge a PDF, the pages are combined in your device's memory. When you format JSON, the parsing happens in your browser tab. No files are uploaded because there's no server to upload them to.

How it works

The site is built with Astro for static page delivery and React for interactive tool interfaces. All processing uses native browser APIs — the Web Crypto API for hashing, Canvas for image manipulation, and JavaScript's built-in encoding functions. No backend, no database, no file storage.

This means every tool works offline once the page has loaded. You can use useonlinetools on a plane, in a secure environment, or anywhere connectivity is limited.

The tools

We currently offer 24 tools across three categories:

• PDF tools — merge, split, compress, convert, rotate, watermark, and unlock PDFs
• Image tools — compress, resize, crop, convert, rotate, flip, and watermark images
• Developer tools — JSON formatter, Base64 encoder, JWT decoder, URL encoder, hash generator, UUID generator, regex tester, and timestamp converter

Open source

useonlinetools is open source. The entire codebase is available on GitHub — you can inspect how every tool works, verify the privacy claims, and contribute improvements. Visit the open source page for the repository link.

Contact

For questions, feedback, or bug reports, open an issue on GitHub.