PDF compressors are everywhere. Most of them make one silent trade-off: they shrink your file by making your text blurry, your images blocky, and your scanned documents look like they were photocopied six times. We ran the same 40MB scanned report through every major free tool to find out which ones actually get it right.

What we tested

We used a 40-page scanned business report — the kind where text quality matters — and compressed it to under 5MB in every tool. We then scored each output on:

  • Final file size — did it hit the target?
  • Text legibility — can you read 9pt body copy at 100% zoom?
  • Image quality — do charts and diagrams still make sense?
  • Ease of use — how many clicks to get a result?

The results

1. ClarixPDF — 9.1/10

ClarixPDF's compression hit our 5MB target while keeping body text sharp enough to read comfortably at 100% zoom. The "Recommended" preset balances size and quality automatically, which meant we didn't have to guess. The whole process — upload, compress, download — took under 30 seconds.

Best for: Everyday compression where you need results fast and quality intact.

2. Smallpdf — 8.4/10

Smallpdf produced clean results with good text legibility. The interface is polished and easy to use. The catch: the free tier limits you to a small number of tasks before asking you to subscribe. Fine for occasional use, less so if you're compressing files regularly.

Best for: Occasional users who don't mind a subscription for heavy use.

3. iLovePDF — 8.1/10

iLovePDF offers three compression levels (extreme, recommended, less compression), which is useful. Output quality on the recommended setting was solid. The free tier is generous with no account required, which puts it ahead of some competitors for no-login use.

Best for: Free compression without signing up, especially for occasional users.

4. PDF2Go — 7.3/10

Decent output quality but noticeably slower upload and processing times than the tools above. Fine as a backup option.

5. Sejda — 7.1/10

Sejda's free tier limits you to three tasks per hour and files under 50MB. Output quality was acceptable but not as sharp as our top three.

The verdict

For most people, ClarixPDF hits the right balance of speed, quality, and a usable free tier. If you need something with no account requirement and don't mind a busier interface, iLovePDF is a solid free alternative. Smallpdf is worth the subscription if you use PDF tools daily across multiple devices.

Tips for compressing PDFs without killing quality

  • Start with "Recommended" or "Medium" compression — never go straight to maximum.
  • Check the output at 100% zoom before sending — if text looks soft, go back and compress less aggressively.
  • Keep the original — compression is lossy; you can't get quality back from a compressed file.
  • Scanned PDFs vs native PDFs — scanned files are images and compress differently than text-based PDFs. Use a tool that handles both.