Compress PDF Online — Reduce File Size Free

Make a PDF small enough for email or an upload form, with five quality levels to choose from and the file never leaving your device.

Pick one of five levels, from smallest file to sharpest result, and see the size before and after so you know whether it fits. Everything happens in your browser, so the document is never sent anywhere.

Start now — it's free →

How to compress a PDF (3 steps)

1. Open the large PDF.
2. Move the slider to choose a quality level (five levels).
3. Click compress, check how much smaller it got, and download.

Why is the PDF so big?

The cause decides how much compression can help — and sometimes it can't help at all.

• Scans from a copier or scanner — every page is a high-resolution image. These shrink a lot, often to 10–30% of the original size.
• Phone photos turned into a PDF — each page can be a 12-megapixel photo. These shrink the most, sometimes to under 10%.
• Presentations and brochures — many high-resolution illustrations. Expect moderate savings, roughly 30–60%.
• Word documents exported to PDF — mostly text with embedded fonts. They are already small and shrink very little.
• Files that were compressed before — the data has already been reduced once, so they barely shrink and the quality gets worse.

If your file is a text-only document of around 200 KB, there is no point compressing it further. It is already as small as it should be.

What you give up

MyPDF renders each page as an image at a suitable resolution and rebuilds the PDF from those images. This shrinks files a lot and works on any PDF, but there are trade-offs:

• Text can no longer be selected or searched, because it is now part of an image. If the recipient needs to copy text from the document, do not use this method.
• Links, bookmarks, and form fields are removed.
• Very small print may look slightly soft when zoomed in closely.

If the file contains pages you do not need, try deleting pages or removing blank pages first. That often cuts the size with no effect on quality.

How small does it need to be?

• Email attachments (Gmail, Outlook) — limits are typically 20–25 MB. You usually do not need to compress, unless it is a scan of dozens of pages.
• Online filing and application portals — often 2–5 MB per file. A medium quality level usually fits.
• Job application and resume uploads — often 1–2 MB.
• Systems capped at 200 KB — you will need to lower the quality a lot.

Tips that actually work

• Step down gradually — start with a high quality level and only go lower if the file is still too big. Jumping straight to the lowest level can make a document hard to read, and an illegible submission may be rejected.
• Check the result every time — open the pages with important figures, such as amounts or ID numbers, and make sure they are still clearly readable.
• For photos of documents, compress the images first with MyPDF's image compressor and then convert them to PDF. This gives finer control over quality.
• Black-and-white scans usually compress better than colour scans. If the document does not need colour, set your scanner to black and white from the start.

Why compressing in your browser is safer

Files people compress are usually about to be sent somewhere: contracts, job applications, copies of ID cards. Many compression sites upload the file and promise to delete it later. With MyPDF the file never leaves your device. The original is not stored, and the compressed result is kept only in the "Recent files" list in your own browser for 24 hours, which you can clear at any time. To check for yourself, load the page, disconnect from the internet, and try it — it still works.

FAQ

📖 Full guide: Compress a PDF so it fits in email

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