How to compress a PDF
Compressing a PDF means reducing the file size, usually to fit under the limit of an email or an online form. On BestPDFInTheWorld it takes three steps: drop the file into the tool, choose the level, light, medium or strong, and download. The tool draws every page as an optimised image, and that is how scans and photo-heavy PDFs lose more than half their weight. The trade-off is that text is no longer selectable or searchable in the compressed file, so it is worth keeping the original. Everything runs in your browser, the file never leaves your computer, and the tool warns you when the result brings no real reduction. This tool is part of the Premium subscription, EUR 1.99 a month, which removes the limits on every tool and adds OCR. Sign PDF opens on the free plan, with one signature a day.
Verified 2026-08-12
- Three steps, nothing to install: choose the file, choose the level, download.
- Three levels with different purposes: light keeps the visual quality, medium balances for everyday use, strong gives the smallest file.
- It pays off mostly on scans, photo-based PDFs and image-heavy documents, where the reduction usually goes past 50%.
- Every page becomes an image: in the compressed file text is no longer selectable, copyable or searchable with Ctrl+F, keep the original.
- No uploads: all processing runs in the browser. This tool is part of the Premium subscription, EUR 1.99 a month, which removes the limits on every tool and adds OCR. Sign PDF opens on the free plan, with one signature a day.
How to compress a PDF, step by step
Compressing a PDF is a three-step job that takes seconds:
- Open the Compress PDF tool.
- Drop the file into the window, or click to pick it from your computer.
- Choose the compression level, light, medium or strong, and press compress. The processing runs on your computer, not on a server.
- Download the compressed PDF, ready in seconds.
Nothing to install, no account and no upload wait. You see the size before and after, and the tool warns you when the compression brought no real reduction. The Compress PDF page explains in detail everything that changes in the file.
Light, medium or strong: which compression level to choose
The stronger the level, the smaller the file, and the lower the image quality too. The right choice depends on where the result is going:
| Level | When to use |
|---|---|
| Light | Keeps more visual quality, for documents where a sharp image matters: a contract with stamps or a technical drawing. |
| Medium | The everyday balance. |
| Strong | The smallest file, at the cost of more quality loss in the images; right when the goal is fitting under a size limit. |
Not sure where to start? Medium is the everyday balance. If the reduction is not enough, move up to strong; if the sharpness loss is too much, step down to light.
What happens to the text when you compress a PDF
The tool draws every page as an image and rebuilds the PDF from those images. That is the mechanism that lets it shrink scans and photo-heavy PDFs so much, but it has a direct consequence: the compressed file no longer carries a text layer. You cannot select a sentence, copy it, or search for a word with Ctrl+F.
If the document needs to stay searchable or editable, for archiving, for example, or for someone else to edit it, compress a copy and keep the original PDF stored separately. See also the guide Reducing the size of a PDF, which complements this one.
Tips for compressing PDFs
- Keep the original before compressing. The compressed file is rebuilt from images: it loses the selectable text and also the document properties, such as author or keywords. The original is the copy that keeps the searchable text.
- If the PDF is already light, do not expect miracles. A mostly-text document, like a contract exported from Word, is already efficient to begin with, compressing it shrinks it little or nothing, and in rare cases the result can even come out bigger, because the image weighs more than the vector text it replaces. The tool warns when there is no real reduction; the guide The compressed PDF got bigger explains why.
- Use the strong level when the goal is fitting under a limit. Email attachments and application forms usually reject files above a few megabytes, that is where strong pays off.
- It works on your phone and offline. The tool was built for small screens, and once the page has loaded once you can compress with the network off, the work is all done by your processor.
- Compressing is not merging. If what you want is to combine several PDFs into one, with the text intact, use the Merge PDF tool.
Is compressing PDFs free? What are the limits?
This tool is part of the Premium subscription, EUR 1.99 a month, which removes the limits on every tool and adds OCR. Sign PDF opens on the free plan, with one signature a day.
| Plan | What it allows |
|---|---|
| Free plan | Only Sign PDF opens without paying, with one signature a day and files up to 10 MB. |
| Premium (EUR 1.99/month) | This tool is part of the subscription: no limits anywhere, plus OCR and larger batches. |
Questions about compressing a PDF.
Is the text still selectable after compressing?
No. The tool draws every page as an image and rebuilds the PDF from those images. Once compressed, the file no longer carries a text layer: you cannot select a sentence, copy it, or search for a word with Ctrl+F. If the document needs to stay searchable or editable, compress a copy and keep the original.
I compressed my PDF and it did not get smaller. Is that normal?
It can be. This tool's compression works on images, and a PDF that is already mostly text is already light to begin with, compressing that kind of file gives little or no gain, and the tool itself warns when it happens. Where it really pays off is scans, photo-based PDFs and image-heavy documents, where the reduction usually goes past 50%.
Which level is best: light, medium or strong?
It depends on where the file is going. Light keeps more visual quality, for documents where a sharp image matters, such as a contract with stamps or a technical drawing. Medium is the everyday balance. Strong gives the smallest file and is the right choice when the goal is simply fitting under a size limit, like an email attachment.
Are my files kept on your servers?
No. Nothing is sent to a server: all the processing runs in JavaScript inside your browser, start to finish, and it keeps working even with the network off once the page has loaded.
Is compressing a PDF free?
No. This tool is part of the Premium subscription, EUR 1.99 a month, which removes the limits on every tool and adds OCR. Sign PDF opens on the free plan, with one signature a day.
Does the compressed PDF keep the document properties?
No. The compressed file is rebuilt from scratch out of the images of each page, so the properties and metadata of the original, author, keywords, do not carry over to the new file.
Does compressing PDFs work on mobile?
Yes. The tool was built for small screens and compresses PDFs directly in your phone's browser, with nothing to install.
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