Runs in your browser with pdf.js and pdf-lib
Compress PDF Files Online — smaller files, text still selectable
Shrink the pictures inside a PDF while text, links and bookmarks stay as they are, or flatten every page for the smallest file. Need it under 100 KB or 200 KB for a form? Pick a target size and the tool keeps the sharpest version that fits.
- PDF files aren't uploaded to our server
- Text stays selectable
- Before and after, page by page
- Free, no account
Make your PDF smaller, and check it before you send it
Add a PDF, pick how far to go, then compare every page with the original.
Drop your PDF here
or browse — one PDF, any number of pages
Looking at what's inside the file…
Your pages
Click a page to see it full size. After compressing, switch to Compressed to compare.
How compression actually works
In most PDFs, the pictures are the weight
Text and fonts take little space. Photos, scans and screenshots saved at full camera size are what make a PDF too big to email.
Two ways to make it smaller
Keep text finds each picture in the file, scales it down to what the page needs and saves it again as a lighter JPEG. Everything else, from text and fonts to links, bookmarks and form fields, is left exactly as it was.
Flatten to images draws each page as one picture at the resolution you choose. It can beat Keep text on scans, but the text becomes part of the picture. pdf.js and pdf-lib do the work in your browser tab, so your PDF isn't uploaded to our server.
What you see before and after
What's inside
As soon as you add a file, the tool counts its pictures and tells you how much of the size they make up, so you know whether compressing will help.
Three strengths
Light, Recommended and Strong, each with its resolution and JPEG quality spelled out.
Before and after
Switch every page between Original and Compressed, or open one full size at 200% to check small print.
An honest result
If a setting makes the file bigger, the tool says so and suggests keeping your original.
How to compress a PDF in four steps
Start with Keep text at Recommended. Only go further if the file is still too big.
Add your PDF
Drop a PDF onto the upload area, or click Select PDF. The bar above the settings shows how much of the file is pictures.
A file that's mostly text won't shrink much, whatever the tool.
Choose how and how much
- Keep text for documents people will read, search or sign.
- Flatten to images for scans that only need to be looked at.
- Light, Recommended or Strong sets resolution and quality.
Compress and compare
Click Compress PDF. When it's done, switch the pages to Compressed, or open one full size and flip between Original and Compressed.
Cancel stops the work at any point.
Check the size and download
The result shows the old and new size and the saving. Rename the file if you like, and download it.
What compressing a scan can do
One scanned report, before and after.
Which settings to use for your file
A starting point for common files. Compare before you download either way.
| File | What matters | Settings to try |
|---|---|---|
| Report or brochure with photos | Photos look fine on screen; text stays searchable. | Keep text, Recommended. |
| Contract or form to sign | Text, form fields and links must keep working. | Keep text, Light or Recommended. Never flatten. |
| Form upload with a size limit (100 KB, 200 KB) | The file must be under the limit and still readable. | Target size with the portal's limit; for a scan, Flatten to images if Keep text can't reach it. |
| Scanned pages for an email limit | Readable on screen, as small as possible. | Flatten to images, Recommended; Strong if still too big. |
| Scan that will be printed | Small print must stay sharp on paper. | Flatten to images, Light, or Keep text, Light. |
| Resume or CV for a job portal | Applicant tracking systems need to read the text. | Keep text only. |
| Slides exported to PDF | Large images on every slide. | Keep text, Recommended or Strong. |
| Text-only document | Already small; few pictures to shrink. | Keep text with document details removed; expect a small saving. |
Settings in numbers
What each strength actually does
Resolution is the most detail a page needs; JPEG quality decides how much fine detail each picture keeps.
Light
Keep text: pictures up to 200 dpi, quality 85%. Flatten: pages at 150 dpi, quality 85%. Good for printing.
Recommended
Keep text: pictures up to 150 dpi, quality 72%. Flatten: pages at 120 dpi, quality 70%. Sharp on screen.
Strong
Keep text: pictures up to 100 dpi, quality 55%. Flatten: pages at 90 dpi, quality 55%. Smallest; check small print.
What's never touched
A picture is only replaced if the new version is clearly smaller. CMYK print images, transparency masks and tiny icons are left as they are, and page sizes never change.
When the result isn't what you expected
Identify the problem, then use the matching fix.
Hardly any saving
The file is mostly text and fonts, or its pictures are already compressed. The bar at the top shows this before you start.
Try Strong. For a scan, try Flatten to images. If neither helps, the file is already compact.
The file got bigger
Flattening a text page turns crisp vector text into a picture, which can weigh more.
Use Keep text instead, or keep your original. The result tells you when this happens.
Small print looks blurry
The resolution is too low for the smallest text in a scan.
Open the page full size at 200%, then try Light.
Text can't be selected
Flatten to images was used, so each page is now one picture.
Compress the original again with Keep text.
It takes a while on a big file
Every picture or page is decoded and saved again on your own device.
Keep the tab open; the progress bar counts pictures or pages. Close other tabs if memory is low.
Still too big for the limit
Some pages may not be needed at all.
Remove pages with Organize PDF or send parts with Split PDF, then compress again.
A password-protected PDF won't open
Encrypted PDFs can't be rewritten by the in-browser PDF libraries.
Remove the password with Unlock PDF, then add the unlocked copy.
Get the size you need on the first try
A working order that avoids a second round.
Read the bar first
If pictures are only a small share of the file, no setting will save much. Don't flatten a text document hoping it will.
Start with Recommended
Move to Strong only if the file is still over your limit, and compare small print when you do.
Keep text for anything official
Contracts, forms and CVs need selectable text. Flatten only scans and photos.
Check the busiest page at 200%
Open the page with the smallest text or the most detailed photo full size, and flip between Original and Compressed.
Compress last
Merge, organize and number pages first. Compressing is the final step before sending.
Keep the original
Detail removed from a picture can't be brought back. Keep the full-quality file for printing or archiving.
Common questions about compressing PDFs
If something's not covered here, the troubleshooting section above likely has it.
Does this tool upload my PDF to a server?
No. The compression runs in your browser with pdf.js and pdf-lib. Your PDF is read on your device and is not uploaded to the AllInOneTools server.
Will my text still be selectable after compressing?
Yes, with Keep text. It only re-saves the pictures inside the PDF, so text, fonts, links, bookmarks and form fields stay exactly as they were. Flatten to images turns each page into one picture, so text can no longer be selected or searched.
How much smaller will my PDF get?
It depends on how much of the file is pictures. The bar shown after you add a file tells you: when pictures are most of the file, Keep text at Recommended often saves a lot; a file that is mostly text will only shrink a little.
Which setting should I choose?
Start with Keep text at Recommended. If the file is still too big, try Strong. If a portal sets a limit such as 200 KB, choose Target size instead. For scanned pages that only need to be read on screen, Flatten to images at Recommended is usually the smallest.
Can I compress a PDF to 100 KB or 200 KB?
Yes. Choose Target size, then 100 KB, 200 KB, 500 KB, 1 MB, or type your own size. The tool tries up to six quality levels and keeps the sharpest file under the limit, counting 1 KB as 1,000 bytes so it also fits portals that count 1,024. A PDF that is mostly text may not get that small with Keep text; the result then shows the smallest size it could make, and Flatten to images usually gets a scan under the limit.
Why did my file get bigger?
Flattening a page with sharp vector text turns it into a picture, which can weigh more than the original text. The result tells you when the file is not smaller, so you can keep your original or use Keep text instead.
Can I check the quality before downloading?
Yes. After compressing, the pages switch to the compressed version, and the Original and Compressed buttons let you flip between them. Open any page full size and zoom to 200% to check small print.
Does compressing change my original file?
No. The tool creates a new, separate PDF for you to download. Your original file is not changed, so keep it if you may need full quality later.
Build notes
The write-up on compressing PDFs in the browser
Because compression runs client-side, I wrote a tutorial on building a browser-based PDF compressor with JavaScript.
How to Compress PDF Files in the Browser Using JavaScript
A step-by-step tutorial on compressing PDFs client-side with JavaScript.