The short answer
Selecting, dropping, or pasting an image does not send that image to Squeezr’s host. The application reads the file through browser APIs and passes its bytes to a local Web Worker. The worker returns a local result that your browser can preview or save.
What the network loads
On the first visit, the browser downloads the website’s HTML, CSS, JavaScript, self-hosted font, service worker, and compression codecs. Codec WebAssembly is loaded when it is first needed. Those requests contain ordinary web request information, but they do not contain the image bytes or filename selected in the tool.
The site is currently hosted on Vercel. Like any web host, Vercel may process request metadata such as an IP address, user agent, requested path, and timestamp for delivery, security, and operational logging. That infrastructure boundary is separate from the local image-compression pipeline.
What stays on the device
- The selected image bytes and filename.
- Decoded pixel data used by the worker.
- Thumbnail and before-and-after preview object URLs.
- Compressed output blobs and the generated ZIP.
- The light or dark theme preference stored in local storage.
The application code does not create a user account, analytics identifier, tracking event, or application cookie.
When local data is released
Removing a pending item or pressing Clear revokes its thumbnail object URL. Closing a preview revokes the original and compressed preview URLs. Download URLs are revoked shortly after the browser starts the download. Closing or reloading the tab releases the remaining in-memory file state.
The downloaded file or ZIP remains wherever your browser saves it. Clearing Squeezr cannot delete files already written to disk.
Offline behavior
Squeezr is an installable progressive web app. Its service worker precaches the app shell, local font, worker code, and codec assets so repeat visits are designed to work without an internet connection after those resources are available. You can verify the boundary yourself: load the tool once, go offline, and compress a disposable image.
Browser and extension boundaries
Local processing protects images from being uploaded by Squeezr, but it cannot control the browser, operating system, downloaded files, or extensions you have granted access to page content. Use a trusted, updated browser and review extension permissions when processing sensitive material.
Open-source verification
The source is available on GitHub. The worker implementation shows the codec imports and local message boundary, while the main-thread code shows object URL creation and cleanup. Read how the complete pipeline works for a guided explanation.
Squeezr is an experimental personal tool. Keep original files and avoid treating any browser compressor as the only copy of important or archival data.