How to Compress a PDF for Email or Upload
Start with the receiving limit
An email service or upload form may impose its own limit, and the limit for an entire message can differ from the limit for an individual file. Check the recipient's instructions first. Leave some room below the stated limit: attachment encoding and other files can make a message larger than the file shown on your device.
Choose a compression mode
Open Compress PDF and add the file. Recommended reduces images while keeping text and vector content; start here when someone needs to select text, follow links, or print a document. Strong converts pages to images. That can help with scanned pages, but selectable text and links no longer work as before. It is not a replacement for a proper archival or accessible document.
The tool starts at 150 DPI and 70% image quality. Press Compress PDFs, compare the displayed sizes, and download the result. If it is still too large, try a lower resolution and quality on the original file, not repeatedly on an already compressed result. Smaller settings can make small lettering, signatures and photographs less legible. There is no exact target-size control, so you may need to try more than one setting.
Inspect before sharing
Open the new file and compare the first, middle and last pages with the original. Zoom into fine print, charts and photos. In Recommended mode, try selecting text and following a link if those functions matter. For a scan, check that faint handwriting and numbers remain readable. If it will be printed, test a page at the intended print size. Do not delete the original until the recipient confirms the file works.
Why a PDF may not shrink
A file consisting mostly of text or already optimized images may have little to remove. The compressor returns the original when its result would be larger. Removing irrelevant pages with Organize PDF can be more effective than reducing image quality. A scan that needs to be searchable should be processed with OCR separately; compression itself does not recognize text.
Compression happens in the browser for this tool. Emailing or uploading the result sends it to the service you choose, so check that service's own privacy terms before sharing sensitive documents.
Worked size check
Imagine a form allows a 5 MB PDF and your original is 8 MB. Try Recommended with the defaults and inspect the new size. If the output is 4 MB and the recipient accepts it, first check a representative chart and a page of small text. If the output is still over 5 MB, try a lower image setting on the original; the resulting size depends on the images and structure in that particular PDF, so no setting can promise a specific result.
For an email, remember that the total message can include other attachments. When a document must be both small and searchable, test text selection after compression. If the smaller file fails a readability check, ask the recipient about another permitted delivery method rather than making an unreadable copy.
Common questions
Why is the compressed file almost the same size?
A document made mostly of vector text or images that were already optimized has little for image compression to remove. Repeated compression can make pictures worse without helping the file fit. Consider removing unnecessary pages, checking whether the recipient accepts multiple files, or using an approved alternative delivery method. Always follow the recipient's instructions.
Should I choose Strong for every scan?
Not automatically. Strong converts every page to an image, which changes the ability to select or search text and follow links. It may be useful when a scan is already image-based and the smaller result is still readable. A document with an existing OCR layer can lose that layer, so compare the original and output before choosing it.
What if a signature or chart becomes hard to read?
Start again from the original and choose a higher resolution or image quality. Examine small numbers, thin lines and handwritten marks at the size the recipient will use. If the requirements include printing, print a representative page or use a PDF viewer's print preview. A smaller file is not helpful if the recipient cannot read the information.
Can this guarantee a size such as 1 MB?
No. The output depends on the source content and selected settings. The tool shows the result size but does not provide an exact-size target. A mostly photographic PDF and a mostly text PDF of the same starting size can behave differently. Leave extra margin where an email system counts encoded attachments as part of the message.
Is the original changed?
The tool produces a separate downloadable result. Keep the original in your own storage until you have compared it with the compressed copy and confirmed that the destination accepts it. The browser performs compression, while sending the completed file by email or uploading it to a form is a separate action.