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How to Compress a PDF

Published June 9, 2026 · 4 min read · By DownloadReels

Upload portals love to reject PDFs for being “too large” — a scanned document can easily be several megabytes when the limit is 500 KB. Compressing a PDF shrinks it so it actually uploads, and you can even target an exact maximum size in KB, all securely.

1
Choose a PDF

Drop or pick the PDF you want to make smaller. It loads instantly and stays private.

2
Pick a level or target KB

Choose a compression level, or type a target maximum size in KB to fit an upload limit.

3
Compress

The pages are re-rendered and re-compressed into a smaller PDF securely.

4
Download

Save the smaller PDF, ready to upload or email.

How PDF compression works here

A PDF’s size is usually dominated by the images and scans inside it. This tool renders each page and re-saves it as a compressed JPEG inside a new PDF — and if you set a target KB, it automatically tunes the image quality until the file fits under your limit. That’s why it can hit a specific size like 200 KB or 500 KB that portals demand.

When to use it (and when not to)

Tip: If you only need fewer pages, the size drops naturally — and if the file is several PDFs, merge them first so you compress everything in one pass.

Compress your PDF now

Shrink a PDF to fit any upload limit — set a target KB and download — free and private.

Open the Compress PDF tool →

Frequently Asked Questions

Can I compress a PDF to exactly 500 KB?

Yes — enter 500 as the target max KB and the tool tunes the quality to land the PDF under it.

Is my PDF uploaded?

No. Compression runs securely, so your document is never stored.

Will the text still be selectable?

The pages are rasterised to shrink the file, so the result is image-based. Use the High level if you need to keep quality close to the original.

What files compress the most?

Scanned and image-heavy PDFs shrink the most; text-only PDFs are already small.

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