I built 45+ free tools that process files entirely in the browser — here's the architecture
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…
Most of the free tools available for compressing images, converting PDFs, and performing various other tasks operate on a similar principle: users upload their file to a server, the file is processed, and then the processed file is sent back to the user. In an effort to avoid this, ToolHub was created. The platform currently hosts over 45 tools that run entirely in the browser, ensuring that files never leave the user's device.
The site features a range of image tools, including a compressor, resizer, cropper, and format converter. These tools are processed client-side, with live before/after previews. Additionally, there are PDF tools for merging, splitting, compressing, and converting files to and from Word, Excel, and PowerPoint formats. Building the PowerPoint converter proved to be a significant challenge, as no existing client-side library could generate real .pptx files.
To overcome this obstacle, the developer had to manually construct the OOXML structure and validate it using python-pptx before shipping the tool.
The platform also includes developer tools such as a JSON formatter, regex tester, hash generator, Base64 encoder/decoder, and UUID generator. Color tools are another highlight, offering a color picker that samples real pixel values from an uploaded image, a palette generator, and format converters. Social tools like a YouTube thumbnail downloader and an Instagram image resizer are also available.
The backend is built using React and Vite for the frontend, while the Node/Express/MongoDB framework handles account management, history, and favorites features. Importantly, the actual file processing occurs entirely on the client-side, eliminating the need for server-side file handling. Currently, the platform is still in its early stages of distribution, and the author is open to feedback on the tools and the concept of browser-based, no-upload processing as a potential differentiator compared to other free tool sites.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
