How to check if an online PDF or photo tool uploads your file
A simple check anyone can do in a minute with the browser's Network tab, what the results mean, and what to do on a phone.
Many tools say "secure" or "private" on the page. That can mean very different things. Some process your file inside your browser and never send it anywhere. Others upload it to a server, process it there, and promise to delete it after an hour. Both can be honest. Only the first one keeps your Aadhaar card, marksheet or bank statement on your own device.
You don't have to take anyone's word for it, including ours. Here is how to check.
The quick check on a laptop
- Open the tool in Chrome, Edge or Firefox.
- Open the developer tools: press F12, or Ctrl + Shift + I (on a Mac, Cmd + Option + I).
- Click the Network tab. Click the clear button (a circle with a line through it) so the list is empty.
- Now use the tool with a test file. Pick a file of a known size, for example a 2 MB photo.
- Watch the list. Click the Size column header to sort by size.
What the results mean
- A request that sends about as much data as your file (look for a POST request, with a large request payload) means the file was uploaded.
- Only small requests, such as analytics, ads or fonts, and nothing close to your file's size, means the file stayed in your browser.
- Downloads of code (files ending in .js or .wasm) are the tool itself arriving in your browser. That's normal, and it's how in-browser tools work.
If you're not sure, click a request and open its Payload or Request section. An upload shows your file name or a big blob of data there.
A rougher check on a phone
Phone browsers don't have an easy Network tab. A rough test: open the tool, let the page fully load, then turn on airplane mode and try your file. If the tool still works, it is working on your device. If it fails, that doesn't prove it uploads: some tools load parts of their code only when you press the button. In that case, do the laptop check once.
Clues in the wording
- "Files are deleted after 1 hour" or "after processing" means they were uploaded. There's nothing to delete otherwise.
- "Processed in your browser" or "files never leave your device" is the claim you can verify with the check above.
- A privacy policy that mentions storing uploaded files, or servers in other countries, is describing uploads.
How TaskNinja works
Our PDF, photo and QR tools run in your browser. Try the check on Compress PDF, JPG to PDF or Resize image to KB: you'll see the tool's code arrive, plus analytics and ads requests, but your file is not sent.
Every TaskNinja tool works this way, including the text tools: what you type stays in the tab too. The page does load Google Analytics and AdSense, which set cookies, but they never receive your files or your text. The privacy page explains both.
Why it matters
The files people shrink and convert for forms are often the most personal ones they have: ID cards, certificates, bank statements, signatures. A tool that never receives the file can't lose it, leak it or keep it. It takes a minute to check once, and then you know.
Written by the TaskNinja team. The tool links go to our own free tools.