Reduce a PDF under 5 MB
A “file too large” error is usually a 5 MB or 10 MB limit: a government form, a job portal, an email attachment or a messaging app. Getting under the limit is a matter of finding what is making the file big and shrinking that, rather than shrinking everything.
Almost always the culprit is images. Text, fonts and vector drawings are already tiny; a few scanned pages or photographs can account for nearly all of a file’s size.
This guide shows how to bring a PDF under 5 MB with a browser tool that never uploads your file.
How to Reduce a PDF to Under 5 MB (or Any Size) | LocalPDF
- 01
Open the compress tool
Go to the Compress PDF page. Nothing to install, nothing to upload.
- 02
Add your PDF
Drop in the file that is over the limit. Its page count and size are read locally.
- 03
Start with Balanced
Balanced is usually enough to clear a 5 or 10 MB limit while looking the same to the eye. Try Light first if you only need to lose a little.
- 04
Check the result and go further if needed
See how much smaller it got. If it is still over, choose Maximum, which also downsamples images, or lower the image quality slider.
- 05
Download and recheck the size
Save the file, then check its size in your files app before you upload it.
Questions
How do I reduce a PDF to under 5 MB?
Open the compress tool, add the file and choose Balanced. That clears most 5 MB and 10 MB limits while looking the same to the eye. If it is still too large, choose Maximum or lower the image quality slider, then download and check the size before uploading.
Does compressing a PDF reduce its quality?
Only the images are re-encoded; text, fonts and vector graphics are recompressed losslessly and stay exactly as they were. Light barely changes the images, Balanced is hard to tell apart from the original, and Maximum also downsamples them, which softens photos and scans.
How much smaller will my PDF get?
It depends on what is inside. Scans and image-heavy documents often shrink by well over half. Files that are mostly text are usually already compact and shrink less, because there is little image data to remove.
Is my file uploaded when it is compressed?
No. The compression runs in your browser, on your device. The file is never sent to a server, and once the page has loaded the tool keeps working with your connection switched off.
Why can’t I make it smaller without losing quality?
Because file size is information: a sharp photograph contains a lot of it. The only ways to shrink a PDF are to store the images more efficiently or to keep less of them. LocalPDF does the first as far as it can; the second is a trade-off you choose with the level and quality controls.
What is actually making your PDF big?
Scanned pages and photographs dominate file size. A single colour scan at 300 DPI can be several megabytes on its own, while hundreds of pages of text might be a few hundred kilobytes. Slide decks and reports with large images behave the same way.
That is why compression targets images first. LocalPDF re-encodes them with a modern encoder called jpegli, and at the Maximum level it also downsamples them to 150 DPI at the size they are actually drawn on the page. Text, fonts and vector graphics are recompressed losslessly, so they stay exactly as they were.
Choosing a level
Light barely touches the images and is best when you are close to the limit. Balanced is hard to tell apart from the original and clears most limits. Maximum also reduces image resolution and is for when the target is strict, like a 2 MB cap. If you need finer control, adjust the image quality slider and watch the saved percentage.
If it still will not fit
Two options. Split the document into parts with the split tool and send them separately. Or, if the images are the problem, compress at Maximum and accept a softer look. There is no way to make a photo-heavy PDF both under 1 MB and sharp; something has to give, and it should not be your text.