I built 45+ free tools that process files entirely in the browser — here's the architecture

Anas Khalid — Sat, 22 Aug 2026 10:03:49 +0000

Most free "compress this image" or "convert this PDF" sites work the same way: upload your file to their server, process it, send it back. I built ToolHub to avoid that where possible — most of the 45+ tools on there run entirely in the browser, so the file never actually leaves your device.

A quick sample of what's on there:

Image tools — compressor, resizer, cropper, format conversion, all processed client-side with a live before/after preview
PDF tools — merge, split, compress, and conversion to/from Word, Excel, and PowerPoint (that last one was the hardest to build — no good client-side library exists for generating real .pptx files, so I ended up hand-building the OOXML structure and verifying it with python-pptx before shipping)
Developer tools — JSON formatter, regex tester, hash generator, Base64, UUID generator
Color tools — color picker (samples real pixel values from an uploaded image), palette generator, format converters
A couple of social tools — YouTube thumbnail downloader, Instagram image resizer

Stack: React + Vite frontend, Node/Express/MongoDB backend for the account/history/favorites side — the file processing itself never touches the server.

Still early on distribution. If anyone's got thoughts on the tools, or on "browser-based, no upload" as a real differentiator vs. just another free tool site, I'd like to hear it.

TOOLHUB

DEV Community: Anas Khalid

I built 45+ free tools that process files entirely in the browser — here's the architecture