Some tools process files on your computer. Others upload them to a server and delete them later. The difference matters for contracts, identification, and medical records.
Where the processing happens
The traditional web tool is server-side: your browser uploads the file, a server processes it, and you download the result. The privacy story rests entirely on trust; you can't observe what the server keeps, logs or feeds into something else. "Files deleted after one hour" is a policy, not a property; you have no way to verify it.
The other kind is client-side: the page you load contains the actual editing code (JavaScript and WebAssembly), and when you "open" a file, it goes from your disk into your browser's memory; not over the network. Cropping, merging, signing, rendering: all of it runs on your own processor. Here, privacy is a property of the architecture. There's no server copy to trust anyone about, because none was made. Modern browsers are capable of this: they can decode images and video, render PDFs, and process audio at near-native speed, which is why a browser tab can now do what needed installed software a decade ago.
Check network activity
I wouldn't rely on a site's privacy slogan by itself, including ours. You can watch what happens when a file is opened:
- Watch the network. Open your browser's developer tools (F12), switch to the Network tab, then load a file into the tool and edit it. Uploads are visible as requests with large payloads leaving your machine. On a client-side tool, opening a 20 MB file produces no such request; the network stays quiet.
- Test offline after the tool is ready. Some client-side tools load editing libraries only when first opened. Let the tool finish loading, disconnect Wi‑Fi, and then try to edit a file. Processing that continues offline is evidence that the file operation is local.
Page and advertising data
Client-side processing protects your files. It doesn't make your visit invisible, and a trustworthy site should say so plainly. Loading any web page shares ordinary request data; your IP address, browser type, which pages you visited; with the hosting provider. Ad-supported sites, this one included, also load advertising scripts, and ad networks collect data as described in their own policies (that's what the consent prompt and our privacy policy cover). The distinction that matters: the content of the files you edit is not part of any of that. It stays in browser memory and is gone when you close the tab.
Browser and file-size limits
Editing uses your browser's memory. Feature-length video or a 2,000-page scanned PDF can exhaust it. Video export and image decoding support vary by browser. Work is not stored in the cloud; closing the tab without downloading discards it. A desktop application is a better fit for an hour of 4K footage.
Why this site works this way
The image tools, PDF tools, video editor, and audio editor process files in the browser. There is no file-upload wait, processing queue or account requirement.