How to use FitsUnder
Two short videos, about 25 seconds each. No sound needed.
One file
Set the limit
Type the size the form accepts, or tap a common one like 500 KB or 2 MB.
Drop your file
Drag a PDF or photo onto the page, or choose it. It is compressed right in your browser.
Check and download
Drag the slider to compare before and after, then download the file that fits.
Many files at once
Drop them all at once
Drag several PDFs and photos together. It’s free, with no limits.
Pick how they fit
Each file: every one under the limit. All together: the files share the limit. Create PDF: photos become one PDF.
Download
One ZIP with every file, or one PDF.
Use FitsUnder without internet
Install it as an app: it opens from an icon and works offline, PDFs included. Your files stay on your device either way.
No button? In Chrome or Edge, click the install icon in the address bar. On iPhone or iPad: in Safari tap Share, then “Add to Home Screen”.
Questions
Is 2 MB 2,000,000 bytes or 2,097,152 bytes?
Websites use both. FitsUnder always aims for the smaller number — 2,000,000 bytes for 2 MB, 200,000 bytes for 200 KB — so the file passes whichever one the form checks.
Will my file look worse?
Only as much as the limit forces. FitsUnder starts from the highest quality and steps down until the file fits, and reduces resolution only when lower quality alone would look bad. Compare before and after in the preview before you download.
Can I still select the text in my PDF?
Usually yes. FitsUnder compresses the pictures inside the PDF and leaves text, fonts and links untouched. Only when a limit is too small for that does it turn pages into images — and it tells you when that happens.
Why did my PNG or HEIC photo come back as a JPG?
JPG stores photos many times smaller and every upload form accepts it. Pictures with transparent areas, such as logos, stay PNG.
Is it safe for passports and contracts?
Yes. Your file is read and compressed by your own browser and saved straight back to your device. It is never sent to a server, so nobody else can see it. Want proof? On the right side of the page there is an internet button. Turn off Wi‑Fi or switch on airplane mode: the button turns green and says “Offline”. Compress your file anyway — it works, and the result even shows “Internet: off — compressed on this device only”.
How can I check that my file goes nowhere?
Easily. Open FitsUnder, then turn the internet off: switch on airplane mode or turn off Wi‑Fi. Drag in a photo and compress it — it works, because the compression runs right on your computer or phone. Without internet your file has nowhere to go. That is why we can say it plainly: your files never leave your device, and no one has access to them.
Is it free?
Yes. No sign-up, no watermark, no daily limit.
Can I compress many files at once?
Yes, for free and with no limits. Drop several files together and choose: each file under the limit, all files together under the limit, or everything combined into one PDF under the limit.