How to Compress a PDF to a Smaller Size (Free)

To compress a PDF, you shrink the photos and scans inside it, because they make up most of the file; the text is already tiny. A browser-based tool can do this in seconds without uploading anything: pick a compression level, download the smaller file, and your text stays sharp and selectable.

This guide explains why PDFs get large, which compression setting to choose, and what to do when a file still will not shrink.

Why some PDFs are so large

A PDF is a container. It can hold text, fonts, vector drawings and images, and each of those takes up a very different amount of space.

• Text is almost free. A page of typed text might add only a few kilobytes.
• Fonts add a little, especially when a document embeds several of them.
• Images are the heavy part. A single photo from a modern phone can be several megabytes, and a scanned page is effectively one large photo.

That is why a 40-page report typed in a word processor can be smaller than a three-page scan of your certificates. When you compress a PDF, the real job is making those images lighter without making the document hard to read.

Choosing the right compression level

TinyTools offers three levels, and picking the right one matters more than anything else.

Light

Light is lossless: nothing you can see changes. It only removes structural overhead from the file. Use it when the PDF must look exactly like the original, but expect small savings.

Balanced

Balanced is the right choice for almost every document. It re-encodes the photos and scans inside the PDF at a sensible resolution and leaves the text completely alone. Text, lines and diagrams are drawn as vectors, so they stay perfectly sharp, and you can still select, copy and search the text afterwards. The difference in the images is usually only noticeable if you zoom right in.

Maximum

Maximum flattens every page into an image to get the smallest possible file. The trade-off is real: the text becomes part of a picture, so it can no longer be selected or searched. Use it only when the size limit is strict and Balanced was not enough.

How to compress a PDF with TinyTools

The tool below runs entirely in your browser, so your file never leaves your device.

1. Drag your PDF into the box, or tap to choose one from your device.
2. Leave the level on Balanced unless you have a reason to change it.
3. Click compress. Larger documents take a little longer, and you will see progress as pages are handled.
4. Compare the original and compressed sizes, then download the smaller file.

If compressing would actually make the file bigger, which happens with PDFs that are already well optimised, the tool tells you and leaves your original untouched rather than handing you a worse file.

How much smaller will your PDF get?

It depends entirely on what is inside.

• Scanned documents and photo-heavy PDFs often shrink by 60–90%, because the images are nearly the whole file.
• Mixed documents, such as a report with a few photos, shrink by a moderate amount.
• Text-only PDFs may only shrink by a few percent. There is simply not much to remove.

If a text-only PDF is still too large, look for something hidden inside it: a high-resolution logo repeated on every page, embedded fonts, or a cover image. Those are usually the culprits.

Tips for getting the smallest file

Remove pages you do not need

Every page you send costs space. If the form only asks for the first two pages of a document, use Split PDF to extract them before compressing. Removing a single scanned page can save more than any compression setting.

Shrink photos before they go into the PDF

If you are building a PDF from phone photos, compressing the photos first gives you more control. Compress Image lets you choose a quality level, and around 80% is usually a large saving with very little visible difference. Then combine them into a PDF.

Compress once, at the end

If you are combining several files with Merge PDF, merge first and compress the finished document once. Compressing each part separately and then compressing again rarely helps and takes longer.

Scan at a sensible resolution

If you control the scanner, a document intended for screen reading does not need the highest resolution setting. A lower setting produces a smaller scan that is still easy to read, which means less to compress later.

Common mistakes to avoid

• Jumping straight to Maximum. It gives the smallest file, but the text stops being selectable. Some reviewers search or copy from documents, and a flattened PDF makes that impossible. Try Balanced first.
• Compressing a document you will edit later. Keep the original. Compression is for the copy you send, not the master file.
• Not checking the result. Open the compressed file and scroll through it before you send it. Make sure every page is there and readable, especially stamps, signatures and small print.
• Expecting a text-only PDF to shrink dramatically. If it is mostly text, it is probably already small. A modest saving is normal.

What a browser-based compressor can and cannot do

Because TinyTools does the work on your own device, there is no upload, no waiting in a queue and no copy of your document sitting on someone else's server. That matters when the file is a payslip, bank statement or contract.

The trade-off is that the work uses your device's memory. We do not set a size limit, but files up to roughly 100 MB are usually fine on a desktop computer, while a very large file on an older phone may run out of memory. If that happens, try a computer, or split the document into parts and compress each one.

Compression also cannot work miracles. If a portal demands a size that your document cannot reach even at Maximum, the answer is to send fewer pages or rescan at a lower resolution. If you are working to a specific limit for an application, see our guide to reducing PDF size for job, school and exam portals. If the problem is email, what to do when a PDF is too large to email covers the options.

Frequently asked questions

How do I compress a PDF without losing quality?

Use the Light level for a lossless result where nothing visible changes, or Balanced, which only reduces the resolution of embedded images. With Balanced, text and line drawings stay perfectly sharp because they are vectors, not pixels.

Why did my PDF barely get smaller?

It is probably mostly text, or its images are already compressed. Text takes up very little space, so there is not much to remove. Splitting out unneeded pages is often the only way to make it meaningfully smaller.

Will the text still be selectable after compressing?

Yes, at Light and Balanced. Only Maximum flattens pages into images, which means the text can no longer be selected, copied or searched.

Is it safe to compress a PDF online?

With TinyTools, the PDF is never uploaded. It is read and processed inside your browser and disappears from memory when you close or reload the page, so sensitive documents stay on your device.

Can I compress a PDF on my phone?

Yes. The tool works in a mobile browser with no app or sign-up. Very large files may be too much for an older phone's memory, in which case a computer will handle them more comfortably.

Ready to shrink your file? Open Compress PDF, drop in your document and download a smaller copy in a few seconds.