How to make a PDF small enough to email
Quick answer
Open the DO101 PDF Compressor and drop in the file. Try the safe mode first: it keeps text selectable and works well on PDFs that were saved inefficiently. If the PDF is a scan or full of photos and still too big, switch to the stronger mode, which re-draws each page as an image and shrinks scans dramatically. Both run in your browser.
Open the Compress PDF — freeStep by step
- 1Open the PDF Compressor and drop in the PDF.
- 2Run the safe mode first and check the before and after sizes it shows.
- 3If it is still too large and the PDF is a scan, choose the stronger mode and lower the image quality until it fits.
- 4Download the result and keep the original.
How big is too big for email?
Gmail accepts attachments up to 25 MB and Outlook up to 20 MB, but attachments grow by about a third when they are encoded for sending, so a file that is only just under the limit can still bounce. Aim for comfortably under — 10 to 15 MB is safe almost everywhere, and many company mail servers set a much lower limit of their own.
The two ways DO101 compresses, and what they cost
The safe mode rewrites the file's internal structure. Text stays text, and nothing about how the document looks changes. On a PDF exported by modern software the saving is often small, because there is little waste to remove — the tool tells you when a file did not get smaller rather than handing you a copy that is no better.
The stronger mode renders each page to a JPEG and rebuilds the PDF around those images. A 30 MB phone scan can fall to a few megabytes. The price is that the result is a picture of your document: the text can no longer be selected, searched or copied. That is usually fine for a signed form you are sending back, and not fine for a report someone needs to quote from.
If it still will not fit
Split it. The PDF Splitter cuts a document into parts by page range, and two 12 MB attachments send where one 24 MB file does not. Or send only the pages that matter with the Page Extractor.
Frequently asked questions
Why did my PDF barely shrink?
It was already efficiently built, which most PDFs from Word or Google Docs are. The big savings come from scans and image-heavy files, and those need the stronger mode.
Why do some websites compress more?
Server-based compressors can re-encode just the images inside a PDF and leave the text alone. That needs a full PDF rewriter, which a browser cannot do reliably, so DO101 offers the two methods it can genuinely deliver and labels them.
Is my PDF uploaded?
No. Both modes run on your device.
The tool for the job
Make a PDF smaller, with an honest choice about the trade-off.