Compress PDF
Reduce PDF file size while preserving quality.
This tool runs entirely in your browser. Your data never leaves your device — nothing is uploaded to our servers.
About Compress PDF
Almost all avoidable PDF bloat comes from one place: images embedded at far higher resolution than anything needs. A phone-scanned page can carry a 12-megapixel photo behind text that will only ever be viewed at screen size. Compression here works by downsampling and re-encoding those images while leaving text and vector content untouched, which is why a scanned document may shrink by 80% while a text-only report barely moves — there was nothing to reclaim in the first place.
When to use Compress PDF
Email attachment limits
Most mail servers reject attachments over 20–25 MB. Scanned contracts routinely exceed that and compress well, because the scan resolution is far beyond what the recipient will view.
Government and exam portals
Upload forms frequently impose hard caps such as 2 MB. If you need an exact ceiling rather than 'smaller', use the target-size compressor, which iterates until it lands under your limit.
Slimming a slide deck export
Slides exported to PDF embed full-resolution images for every copy of a background. Compression removes that redundancy without touching your text.
Limitations worth knowing
- A text-only or vector-only PDF will barely shrink. There is no redundancy to remove, and a tool promising otherwise is discarding something you wanted.
- Compression is lossy for images. Fine print in a low-quality scan can become harder to read.
- Already-compressed PDFs (previously optimised, or exported small) yield little further reduction.
- The tool cannot compress encrypted files.
How to compress pdf
- 1
Upload the PDF you want to shrink.
- 2
Run the compressor and compare the reported output size against the original.
- 3
Open the result and check any image-heavy pages before relying on it — compression is a quality trade-off by definition.
- 4
If you need to hit a specific limit such as 2 MB, use the target-size version of this tool instead.
Frequently asked questions
Why did my PDF barely get smaller?+
Because it was probably already efficient. Compression reclaims space from over-sized embedded images. A PDF that is mostly text and vector graphics has very little to reclaim, so a 5–10% reduction is a correct result, not a failure.
Will compression make my text blurry?+
Not for real text. Text and vector content pass through untouched and stay sharp at any zoom. Only embedded images are re-encoded — so a scanned page, which is entirely an image, can lose detail while a typed document will not.
I need the file under an exact size. Can this guarantee that?+
This tool compresses once with sensible settings. For a hard ceiling, use the target-size compressor, which repeatedly adjusts quality until the output lands under the size you specify — the right choice for portals that reject anything over a stated limit.
Compress PDF to an exact size
Need to hit a strict upload limit for an exam, government or admission form? Use a target-size compressor that reduces your PDF to a specific size automatically:
Troubleshooting Compress PDF
The file barely got smaller
Why it happens: Compression reclaims space from oversized embedded images. A PDF that is mostly text and vector graphics has almost nothing to reclaim, and an already-optimised file has none.
How to fix it: Check what the document actually contains. If it is a text report, a 5-10% reduction is the correct result and no tool will do better without destroying something. If it contains scans, the images are where the size is.
Text in my scanned document is now hard to read
Why it happens: A scanned page is entirely an image, so image compression applies to the text itself. Push quality too low and fine print degrades.
How to fix it: Re-compress from the original at a higher quality setting. Scans of small print need gentler settings than photographs do.
I still cannot get under the portal's size limit
Why it happens: General compression targets a quality level, not a file size, so it cannot guarantee a specific ceiling.
How to fix it: Use the target-size compressor, which iterates until the output lands under the limit you name. If it still cannot reach it, split the document and upload it in parts.
Nothing happens when I try to compress
Why it happens: The file is encrypted, so its content streams cannot be read or rewritten.
How to fix it: Open it in a PDF reader with the password and save an unprotected copy first.
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