Utilities that treat your files like they’re yours
onthisdevice is a set of 417 free tools for the small, annoying jobs: merging a PDF, shrinking a photo, converting a spreadsheet, working out a mortgage payment. The difference is where the work happens: entirely inside your browser, on the machine you are already using.
Why this exists
The typical online converter works like this: you hand a stranger your document, it lands on a server in a country you didn’t choose, a job queue picks it up, and a policy page assures you it will be deleted in an hour. Then you are asked to sign in, wait out a countdown, or pay to remove a watermark from your own file.
Browsers stopped needing that years ago. Modern JavaScript engines and WebAssembly can parse a PDF, re-encode a JPEG, run FFmpeg or hash a file faster than most connections can upload it. The upload step survives because it justifies the subscription, not because the task requires it.
So we removed it. Every page here is static; every computation runs on your CPU. That single change makes the tools private, fast and unmetered, and it removes the running costs that force everybody else to put a paywall in the way.
How to verify the claim
Don’t take our word for it. This is the rare privacy promise you can check yourself in about fifteen seconds:
- Open any tool page and load your browser’s developer tools.
- Switch to the Network tab and clear it.
- Drop in a file and run the tool. You’ll see requests for code and WebAssembly modules, and not a single request carrying your file.
- Turn off your network and run it again. The page and its engine are already loaded, so it still works.
What we’re deliberately not building
Anything that needs a server breaks the promise, so it stays out: live currency rates, IP lookups, cloud storage integrations, shortened share links, account sync. If a feature can only exist by sending your data somewhere, it doesn’t belong here. A slightly smaller toolbox is worth an unambiguous guarantee.
What it costs
Nothing, and there is no premium tier waiting in the wings. Serving static files is cheap; processing your 400 MB video is free because your laptop does it. There are no ads, no affiliate links, no analytics scripts and no email capture. Read the privacy page for the exact list of what we don’t collect.
Local by default, not by promise
A privacy policy is a statement of intent. An architecture with no upload endpoint is a fact. Every tool here reads your file with the browser File API and processes it in this tab. There is nowhere for it to go.
Fast enough to feel instant
Pages are static HTML with a small island of JavaScript. Heavy codecs load only when you actually use them, and long jobs report real progress instead of a spinner that lies.
One job, done completely
Each tool solves one problem properly: sensible defaults up front, advanced options behind a disclosure, real error messages, and output you can always download or copy.
No dark patterns
No watermark you have to pay to remove, no daily quota, no “create an account to download”, no interstitial ad between you and your file. There is no upsell because there is no upgrade.
What’s in the toolbox
417 tools across 16 categories.