Client-side browser tools edit files on your own computer and never send them to a server. Server-side tools upload the file and promise to delete it later.
Where the processing happens
Server-side tools upload the file, process it remotely and return the result. You cannot see what the server keeps or logs, and "files deleted after one hour" cannot be verified.
Client-side tools ship the editing code (JavaScript and WebAssembly) with the page. Opening a file loads it from disk into browser memory without a network transfer. Cropping, merging, signing and rendering run on your processor. Modern browsers decode images and video, render PDFs and process audio at near-native speed. The image tools, PDF tools, video editor and audio editor on this site work this way, with no upload wait, queue or account.
Check network activity
To verify local processing on any site:
- Open developer tools (F12) and the Network tab, then load and edit a file. Uploads appear as requests with large payloads. On a client-side tool, a 20 MB file produces none.
- Let the tool finish loading (some load libraries on first use), disconnect Wi‑Fi, and edit a file. If it still works offline, processing is local.
Page and advertising data
Client-side processing protects file contents only. Loading any page shares request data (IP address, browser type, pages visited) with the host. This site is ad-supported, and ad networks collect data under their own policies, covered by the consent prompt and the privacy policy. File contents are never part of that data and are cleared from memory when you close the tab.
Browser and file-size limits
Editing uses browser memory, which feature-length video or a 2,000-page scanned PDF can exhaust. Video export and image decoding support vary by browser. Nothing is saved to the cloud, so closing the tab without downloading loses your work. Use desktop software for an hour of 4K footage.