How much smaller will my PDF be?

Scanned and image-heavy documents typically drop 40-80%. A PDF that is already mostly text barely changes, because there are no images to re-encode — that is not a failure, it means the file was already efficient.

Will compression ruin the quality?

The light preset is close to visually lossless. The strongest preset lowers image resolution enough that small print and watermarked scans can look soft, so use it for email attachments, not for archival copies.

Can I compress a password-protected PDF?

Unlock it first with Unlock PDF, compress the result, then protect it again if it needs a password.

Why did my 5 MB PDF not shrink at all?

Most likely it holds vector text and embedded fonts rather than photos. Try the strongest preset; if nothing moves, the file is already near its floor.

Compress PDF

Shrink PDF file size with three strength presets and see exactly how much you saved.

Drag & drop your PDF here

or click to browse — .pdf · up to 1 files

Compression strength

Balanced for everyday documents. Pages are rebuilt as optimized images, so text in the output is no longer selectable — keep the original if you need search-friendly PDFs.

Add a PDF first.

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About Compress PDF

Compress a PDF by re-encoding the images inside it, which is where almost all of a PDF's weight lives. Three strength presets cover the usual needs — keep it near-identical, make it much smaller, or shrink it hard for email — and the before-and-after size is shown on screen before you download.

Getting an attachment under a mail server's size limit without losing the text layer.

How to use Compress PDF in 3 steps

Drop the heavy PDF onto the drop area.
Pick a compression strength — the preview shows the new size before you commit.
Download the smaller PDF and compare the two file sizes.

What you get with Compress PDF

Before-and-after size shown on the page, so you can see what you got
Text stays selectable and searchable — only image data is re-encoded
No watermark, no page-count limit and no account to shrink a file
Runs in your browser — the file is never uploaded
Works on desktop and mobile, no install

Compress PDF: questions

How much smaller will my PDF be?: Scanned and image-heavy documents typically drop 40-80%. A PDF that is already mostly text barely changes, because there are no images to re-encode — that is not a failure, it means the file was already efficient.
Will compression ruin the quality?: The light preset is close to visually lossless. The strongest preset lowers image resolution enough that small print and watermarked scans can look soft, so use it for email attachments, not for archival copies.
Can I compress a password-protected PDF?: Unlock it first with Unlock PDF, compress the result, then protect it again if it needs a password.
Why did my 5 MB PDF not shrink at all?: Most likely it holds vector text and embedded fonts rather than photos. Try the strongest preset; if nothing moves, the file is already near its floor.