Zero-storage promise
Compression, grayscale, format conversion, watermarking and the rest of JustFileKit run entirely in your browser, and your files are never uploaded to any server. That is not a slogan; it is a fact about how the site is built, and you can check it.
Verify it yourself
- Open the Network tab in your browser developer tools: while a file is being processed, no file content ever leaves the page.
- The site has no server endpoint that receives file content.
- Our Content Security Policy only permits the site's required services, analytics, advertising and error reporting; the processing code never sends file content to any of them.
What we store, and what we do not
- Never stored: file content, file names, or processed results.
- Stored: your email address and account identifier after sign-in. The tools are free without signing in.
- First-party stats: aggregate page views, tool calls and processed-file counts only; no IP addresses or file names are stored.
How error reports protect you
To fix problems, the app reports the error message and stack trace when something breaks. Everything is scrubbed before it is sent:
- Anything that looks like a file name (for example
contract.pdf) is replaced with [filename] before sending. - URLs that could carry file content, such as blob: and data:, are stripped out.
- No cookies, no request bodies, no email address, no identity information is sent, and there is no session replay.
- These scrubbing rules are covered by automated tests, and the code is public so you can read it.
Traffic analytics and advertising
- The site may use Google Analytics and Cloudflare Web Analytics to understand page traffic, referral countries and device types.
- The site may display ads through Google AdSense. Depending on consent, Google may use cookies or similar technologies to deliver, measure and personalize advertising.
- Where required, Google's consent management platform lets you accept, reject or manage these choices. These services never receive the files you process.