Compress PDF to 1 MB
Bring a long scan, a PDF of phone photos or a report under 1 MB for an upload portal. Your file is compressed on this device and never uploaded.
- 100% free
- Runs in your browser
- No uploads
- Runs on your deviceEvery tool works directly in your browser. No files are uploaded.
- Your privacy mattersYour files never leave your device, so there's nothing for us to store.
- No limitsUse any tool as much as you need. No daily caps, no waiting.
- Completely freeNo signup and no trial to cancel. Ads keep the tools free.
How to compress a PDF to 1 MB
- Add the PDF. Drop it on the box or choose it. You can add several; each is compressed on its own.
- Leave the limit on 1 MB. Fit under a size is already selected. Type another number in Other size if your form differs.
- Compress, check and download. The bar shows the new size against the limit. Open the result and zoom in before uploading it.
When a form asks for 1 MB
1 MB is a common limit for a single document on job, university and government portals. It is roomy: in our tests ten colour pages scanned at 300 DPI fitted with their images at 80 DPI, and five phone photos of pages kept about 115 DPI, sharp enough to read small print.
Sites don't agree on what 1 MB means. Some count it as 1,024 KB (1,048,576 bytes), others as 1,000 KB (1,000,000 bytes). The tool aims at 1,000,000 bytes, the smaller of the two, so a result that fits here passes on either kind of site. File sizes under your PDF are shown the way Windows shows them (1 KB = 1,024 bytes), which is why the limit reads as 977 KB there.
What reaches 1 MB, and what doesn't
We ran sample A4 scans through this page in Chrome. Your files will differ, since busy pages and colour need more space, but the pattern holds: page count and colour decide whether 1 MB is realistic.
| Sample file | Before | After | How |
|---|---|---|---|
| 10-page colour scan, 300 DPI | 12.04 MB | 729 KB | Photos recompressed to 80 DPI |
| 20-page colour scan, 200 DPI | 13.13 MB | 726 KB | Photos recompressed to 60 DPI |
| 5 phone photos of pages, 12 MP | 13.54 MB | 751 KB | Photos recompressed to about 115 DPI |
| 30-page greyscale scan, 300 DPI | 31.90 MB | 846 KB | Pages re-rendered at 50 DPI |
When nothing fits, the tool keeps the smallest version and says it couldn't reach the limit, rather than quietly handing you an unreadable file.
If it won't fit
Don't aim lower than the form asks. If the limit is 1 MB, a 900 KB file is accepted just like a 200 KB one, and it is sharper. Use this page rather than a smaller size "to be safe"; it already allows for both ways of counting.
Thirty pages is pushing it. The 30-page scan above only fitted once its pages were turned into images at 50 DPI. Leave out pages the form doesn't need with Delete PDF pages, or split it if you can upload more than one file.
Reports and slides. A PDF exported from Word or PowerPoint is usually big because of its pictures. Tick Keep text selectable so only the pictures are recompressed and the text stays searchable.
Other sizes
Frequently asked questions
Is 1 MB 1,000 KB or 1,024 KB?
Both are in use. Windows and many websites count 1 MB as 1,024 KB; others, and most storage makers, count 1,000 KB. The tool aims under 1,000,000 bytes, which is below both, so the file passes whichever the portal uses.
Why does the limit show as 977 KB?
1,000,000 bytes divided by 1,024 is about 977 KB. The sizes on this page are shown in the Windows way, so you see the same number your computer shows for the file.
My PDF is only a little over 1 MB. Will it lose much quality?
Often hardly any. The tool first tidies the file without changing anything you can see, then recompresses photos at 150 DPI, and stops as soon as the file fits. The note under the file says which step it needed.
Can I compress a 30 MB scan to 1 MB?
Yes, it handled a 32 MB, 30-page scan in our tests, though only by turning the pages into images at 50 DPI. Large files take longer and use more memory, so on a phone close other tabs first. Nothing is uploaded, however big the file.