You save a document as a PDF, and it is too big. The email will not send, or the upload portal says the file is over the limit. Most email services limit the size of attachments, and many portals accept only a few megabytes. So you need a smaller file.
Compressing a PDF always changes something. Sometimes the change is small and you will never notice it. Sometimes it removes things you need, like text you can search or a signature that must stay valid. This guide explains the two main ways to compress a PDF, how our free tool does each one, and how to pick the right one for your file.
What Makes a PDF Large?
It helps to know what is inside the file before you try to shrink it:
- Scanned pages: A scanner saves each page as one big picture. Many scanners use a high resolution, so a long scanned document can be many megabytes.
- Photos: Camera photos often hold far more detail than a screen can show. A brochure or report with many photos gets big fast.
- Embedded fonts: Many PDFs carry a copy of each font they use, so the file looks the same on every computer. This adds some size.
- Extra data: Comments, form fields, attached files, page thumbnails and document details add a little more.
- Plain text: Typed text is stored in a very compact way. A text-only PDF of many pages can still be small.
In most large PDFs, the pictures are the biggest part. That is why most compressors focus on pictures.
The Two Ways to Compress a PDF
Way 1: Optimize the file and keep the text
This way keeps the PDF as a real document. It shrinks the pictures inside, keeps only the parts of each font that are used, and removes data that is not needed. The text stays as text. You can still select it, copy it and search it. Links and bookmarks usually keep working.
Many desktop PDF programs have a feature for this. Look for a menu item with a name like "reduce file size", "optimize" or "save as smaller file". Many programs that export PDFs, such as word processors, also have a setting for smaller files or lower image quality. How much this saves depends on the file. It works best when the PDF has large photos. It saves less on scans, because the whole page is already one picture.
Way 2: Turn every page into a picture
This way draws each page as an image, saves it as a JPEG, and builds a new PDF with one image per page. The page looks the same, but it is now a photo of the page. You choose how sharp the image is. A lower setting gives a smaller file and a softer page.
This way can shrink scanned documents a lot, because it can store the page at a lower resolution than the scanner used. But it has real costs. The text is no longer text, so you cannot select, copy or search it. Links, bookmarks and form fields are gone. Digital signatures are no longer valid. And a PDF that is mostly typed text may not shrink at all. It can even get bigger, because a picture of text is often larger than the text itself.
| Way 1: Optimize | Way 2: Pages to pictures | |
|---|---|---|
| Text can be selected and searched | Yes | No |
| Links, bookmarks, form fields | Usually kept | Lost |
| Digital signatures | Usually broken too, because the file changes | Broken |
| Scanned documents | Often small savings | Often large savings |
| Text-only documents | Small savings, nothing lost | Little or no saving. The file can grow. |
Which Way FreeToolPoint Uses
Our PDF compressor has two modes, one for each way.
Keep text — shrink images only is the default. It is a simple form of Way 1. Here is what happens inside your browser:
- The tool opens your PDF with pdf-lib and finds the images inside it.
- For each photo, it checks how large the photo is drawn on the page. If the photo has more pixels than the level needs, it is scaled down and saved again as a JPEG.
- The new photo is used only if it is at least 5% smaller. Small images, CMYK print images and some less common image types are left as they were.
- Everything else is copied as it is: the text, the fonts, links, bookmarks and form fields. The text can still be selected and searched.
Keep text mode only shrinks images. It does not trim fonts or remove other data, so a desktop optimize feature can sometimes save more.
Turn pages into images is Way 2:
- The tool opens your PDF with pdf.js, the same PDF reader that Firefox uses.
- It draws each page on a hidden canvas with a white background, at the resolution of the level you picked.
- It saves that canvas as a JPEG image.
- A second library, pdf-lib, builds a new PDF with one image per page. Each page keeps its original size, so an A4 page stays A4.
All of this runs on your device. Your file is not uploaded to FreeToolPoint or anyone else. There are four levels, and they work in both modes. Each one sets the resolution in pixels per inch and the JPEG quality. In Keep text mode they apply only to the photos, so the text stays sharp:
| Level | Pixels per inch | JPEG quality | Good for |
|---|---|---|---|
| Screen | 54 | 22% | Getting under a strict size limit. Photos look rough, and in Turn pages into images mode small print may be hard to read. |
| eBook (default) | 72 | 55% | Email and reading on a screen at normal zoom. |
| Printer | 108 | 78% | Photos and scans that must stay clear when zoomed in, and small print in Turn pages into images mode. Home or office printing. |
| Prepress | 144 | 92% | Keeping as much detail as the tool can. Often saves little. |
Even Prepress is well below the 300 pixels per inch that print shops usually ask for. If a PDF is going to a professional printer, send the original.
When Our Tool Is a Good Choice
- Scanned documents. Receipts, letters, ID copies and other scans are pictures already. Here the tool often saves the most, in both modes.
- PDFs full of photos. Reports, brochures and photo albums with large camera photos can shrink a lot. Keep text mode shrinks the photos and keeps the text, links and bookmarks.
- Email and upload limits. When you only need the reader to see the pages, and the file must fit under a size limit.
- Private files. When you do not want to upload a document to someone else's server.
When Our Tool Is the Wrong Choice
- Signed documents. Contracts with a digital signature, and other signed files, will fail the signature check after compressing, in both modes. Send them as they are.
- Forms or searchable text, in Turn pages into images mode. That mode makes form fields part of the picture, so no one can type into them, and the text can no longer be searched, copied or read by screen readers. Use Keep text mode instead.
- Mostly typed text. A PDF made from Word or a web page is often small already. Neither mode saves much. If the new file is not smaller, the tool tells you and gives you your original back.
- CMYK print files. Keep text mode leaves CMYK images as they are, so it may save little on these.
- Professional printing. The resolution is too low for a print shop.
- Your only copy. You cannot get the detail back from the compressed file.
In these cases, keep the original. If you still need a smaller file, try the optimize or reduce-size feature in a desktop PDF program you already use, and check that the text can still be selected. You can also export the PDF again from the original document with smaller images, split the PDF into parts, or share it as a link from cloud storage instead of an attachment.
Step-by-Step: Compress a PDF with FreeToolPoint
- Open the tool: Go to the FreeToolPoint PDF Compressor.
- Pick a mode: Keep text — shrink images only is selected when the page opens. Choose Turn pages into images only if you do not need to select or search the text.
- Pick a level: Click Screen, eBook, Printer or Prepress. eBook is selected when the page opens, and it is a good place to start.
- Add your PDF: Drop it on the box or click the box to choose a file. The tool works on one PDF at a time. The file is read by your browser and is not sent to a server.
- Click Compress PDF: A progress bar shows which image (Keep text) or which page (Turn pages into images) is being done. Long documents take longer.
- Read the result: You see the original size, the new size, the space saved and the number of pages. In Keep text mode you also see how many images were made smaller. If the new file is not smaller, the tool says so and the button gives you your original file unchanged. See the tips below.
- Try another level or mode if needed: Your file stays loaded. Click another level or mode and press Compress PDF again.
- Download and check: The file is saved as
compressed_plus your original name. Open it, zoom in, and read the smallest text, numbers and dates before you send it.
The tool adds no watermark and needs no account. Very long PDFs, or PDFs with very large pages, use a lot of memory. On a phone, the tab may slow down. If that happens, split the file first and compress each part.
Tips for a Good Result
Start in the middle
Start with eBook. If the file is still too big, try Screen and check that small text is still readable. If the pages look too soft, try Printer. The right level depends on your file, so it is worth trying two.
Check the result before you send it
Open the compressed PDF and zoom to 100%. Look at the smallest text, the numbers, any stamps and any signature. A page that cannot be read may be rejected by the person or portal that receives it.
Do not compress twice
If you run a compressed file through the tool again, the photos or pages are saved as JPEGs once more. Each round adds blur. Go back to the original file and pick a lower level instead.
Keep the original
The download has a new name, so your original stays on your device. Keep it. Compress a copy for sharing, and keep the full file for your records.
Shrink the pictures before you make the PDF
If you build the PDF yourself, you have more control. Resize photos to the size they will be shown at, and shrink them with an image compressor. Then create the PDF, for example with Image to PDF. The text in a document made this way stays as text.
Conclusion
There is no way to compress a PDF that is free of trade-offs. Optimizing the file keeps the text and the links, but it may not save much on scans. Turning pages into pictures can save a lot on scans and photos, but the text, links, forms and signatures are lost.
Our tool offers both ways. Its default Keep text mode shrinks the photos and keeps the text, links, bookmarks and form fields. Its Turn pages into images mode can save more on some scans, but loses the text. Both are a good fit for scanned documents and photo-heavy PDFs that must fit an email or upload limit, and neither uploads your file. For signed contracts, keep the original, because any change breaks the signature.