About utilbrew

Why it works this way

• Your files stay on your device. The usual online tool uploads a PDF or a photo to its server, does the work there and sends the result back. Here your own browser does the work, so a contract, a payslip or a passport scan never leaves your computer or phone.
• No account, no queue and no daily limit. With no server doing the work, there is nothing to ration and nothing to sign in to.
• Every tool says what it does not do. Each tool’s page lists its limits with the reason for each, so you can tell before you start whether it will do the job.
• The details are the point: a JSON formatter that keeps every digit of a number, a PDF merger that copies pages rather than drawing them again, a photo cleaner that leaves the pixels alone.

How it works

The site is a set of static pages and scripts. Once a page has loaded, each tool runs as JavaScript on your device, and a tool with a lot of work to do hands it to a background thread of the same browser, so the page stays responsive. The page’s security policy lets it talk only to the site it came from, and no tool sends your files even there: open your browser’s developer tools, watch the Network tab, and use any tool. What your browser keeps between visits is listed on the Privacy page.

Built with

• pdf-lib by Andrew Dillon, in Cantoo’s fork (MIT): merging, splitting and writing PDFs
• PDF.js by Mozilla (Apache 2.0): drawing the pages of a PDF
• fontkit by Devon Govett, in Cantoo’s fork (MIT): the letters a PDF embeds for a page number or a watermark
• Liberation Sans, Serif and Mono by Steve Matteson for Red Hat (SIL Open Font License): the type of a page number or a watermark
• UPNG.js by Photopea (MIT): PNGs cut to a palette
• noble-hashes by Paul Miller (MIT): the hash algorithms
• jsonrepair by Jos de Jong (ISC): repairing broken JSON
• uqr by Anthony Fu (MIT): the pattern of a QR code
• yaml by Eemeli Aro (ISC): YAML read and written with its comments
• markdown-it by Vitaly Puzrin and Alex Kocharin (MIT): the Notepad’s Markdown
• The long word list by the Electronic Frontier Foundation (CC BY 3.0 US): the words of a passphrase
• Next.js, React and Zustand by Vercel, Meta and Poimandres (MIT): the site itself
• Space Grotesk and JetBrains Mono by Florian Karsten and JetBrains (SIL Open Font License): the type
• The tz database by IANA, read from your browser’s own copy: every time zone and clock change

Every package the site sends to your browser, each with its licence in full: licenses.txt.

Contact

Write to hello@utilbrew.com about a tool that gave a wrong answer, a file one could not open, or a tool you would like. A description of the file helps as much as the file itself, and keeps it on your machine.