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Compress PDF to a Target Size

Set a maximum size for your PDF, or use a quality preset. Every completed target-size PDF is verified before download. 100% browser-based. Zero uploads.

No Upload Required Quality Presets Target Size Control Verified Download

Drop your PDF here

or click to browse files from your device

PDF input: up to 256 MiB on desktop / 128 MiB on phones or low-memory devices.

How it works

Three simple steps – everything happens in your browser.

1

Upload your PDF

Choose one PDF within the displayed device budget. The input stays on your device.

2

Choose quality or target size

Use Low, Medium, or High, or select a strict maximum for the completed PDF.

3

Verify and download

Target-size PDFs are checked against the selected maximum before download.

Why choose ToolKnit for PDF Compression?

100% Private —No Server Uploads

Your PDF never leaves your device. All compression is done locally using modern browser APIs. No data is sent to any server —ever.

Sequential processing, with cancellation

Pages render one at a time. Long or image-heavy documents take longer; cancel and retry with a lower quality setting when needed.

Verified Target Size

Every completed target-size PDF is checked against the selected maximum. A PDF that cannot meet it is not mislabeled as successful.

Control the Trade-off

Target mode adjusts image quality and render scale only as needed, so you can meet upload limits without guessing between presets.

Pro Tips

  • ● Choose a target-size preset such as 500 KB or 1 MB when a website sets a PDF upload limit.
  • ● Use Smart compression when you care more about quality than hitting one exact maximum.
  • ● Both compression modes produce image-based PDFs when rebuilding pages. Keep the original for searchable text, links, forms, bookmarks, or accessibility tags.
  • ● Long documents and very small targets need more processing time and may not meet the limit while remaining readable.
FAQ

Frequently Asked Questions

Can I compress a PDF to a specific file size?

Yes. Choose a target such as 100 KB, 200 KB, or 500 KB, or enter a custom maximum from 50 KB to 50 MB. A target is an upper limit, not an exact final size. Successful outputs are verified before download.

Will every target-size PDF stay below my selected limit?

Completed target-size PDFs are checked against the selected byte limit. If no tested setting meets it, the tool reports a failure and does not offer an oversized download as successful. Review readability separately.

What changes in the compressed PDF?

In both Smart and target-size modes, rebuilt PDFs contain JPEG page images. Page dimensions remain, but detail can decrease; selectable text, working links, forms, bookmarks, and accessibility tags are lost. An unchanged original retains its existing features.

Are my PDF files uploaded to a server?

No. All compression happens locally in your browser. Your files never leave your device.

How much smaller will my PDF be?

It depends on the content and the selected maximum. Image-heavy PDFs usually shrink most, while text-only PDFs that are already optimized may not need compression or may not reach a very small target without harming readability.

What is the maximum file size I can compress?

Input PDFs can be up to 256 MiB on desktop or 128 MiB on phones and low-memory devices. This is separate from the target output range of 50 KB to 50 MB. Page dimensions, encoded output and available memory also limit conversion. 1 MiB is 1,048,576 bytes.

Meet an upload limit without losing track of the original

Choose 100 KB, 500 KB, or a custom maximum, then inspect the downloaded pages. Learn when image-based compression fits your task and why a result can stay unchanged or fail.

Read the PDF size-limit guide