About compress PDF for email
Mail systems limit attachments or total message size, often somewhere between 10 and 25 MB, but the applicable limit depends on both providers and on whether they count the encoded message. Base64 transport encoding adds roughly a third to an attachment's bytes, so a file below a published figure can still be refused once encoding, message text and other attachments are counted. Leave headroom and confirm the rules rather than assuming an on-disk size guarantees delivery. This page fixes the image-resolution target at 110 DPI and lets you adjust JPEG quality independently. Downsampling uses recoverable placement in supported images; images below the target may still be re-encoded, and skipped images may be unchanged. Small scanned text, zoomed images or print output can reveal lost detail, so a higher quality setting is not a substitute for a higher DPI target. Use the main Compress PDF page if you need to change resolution. Object-stream rewriting also runs, and metadata cleanup is requested by default: it targets eight standard Info keys and detaches the catalog XMP reference, without erasing every metadata store or detached XMP bytes. The attachment may still carry private information. Only a smaller complete rewrite is returned; otherwise the original bytes, images and metadata are returned unchanged. Compare the actual result before attaching it and keep the original.
How to compress PDF for email
- 01
Check both ends
Find your provider's limit, and remember the recipient's may be lower. Aim well under the smaller figure.
- 02
Add the attachment
Load one unencrypted PDF, up to 250 MB and 5,000 pages. The 110 DPI target is fixed here; it is not a guarantee that every image will have that resolution.
- 03
Adjust for the recipient
Adjust JPEG quality and inspect small text or images. For a different DPI target, use Compress PDF. Optional grayscale affects only supported image replacements, not every colour on the page.
- 04
Compress, then attach
Read the returned size, download and inspect that file before attaching it. The -compressed.pdf suffix may contain unchanged original bytes. Leave headroom for message and encoding overhead.
What this tool does
- Fixed 110 DPI downsampling target with independently adjustable JPEG quality
- Limited metadata cleanup requested by default, without a secure-erasure guarantee
- Optional grayscale for supported image replacements, without changing text or vector colours
- Local preparation without uploading the PDF to a conversion server; sending the email is a separate step
- Size reported before you attach, so you are not guessing at the mail client
Limitations worth knowing
Every PDF tool has constraints. Stating them plainly is more useful than discovering them halfway through your work.
- Mail providers set their own attachment and message limits; this tool cannot detect them. It accepts one PDF up to 250 MB and 5,000 pages, which does not imply email eligibility.
- Encoding and other message content add bytes. A file below a stated limit can still be rejected; leave headroom and check the provider's rules.
- Long scans may not fit the intended mail limit at usable quality. Split them only if the recipient accepts parts, or agree on another delivery method.
- The 110 DPI target cannot be raised on this page and may soften images in print or at zoom. Use Compress PDF for a different target; higher JPEG quality alone cannot restore discarded pixels.
How your file is handled
This tool runs entirely inside this browser tab. When you choose a file, your browser reads it from your own disk and hands the bytes to JavaScript running on this page — no network request carries your document anywhere. You can confirm that yourself: open your browser’s developer tools, switch to the Network panel, and run the tool. You will see no upload.
Nothing is stored after the fact. Closing or reloading this tab discards the file, the result and everything derived from them, because none of it ever left your machine. Read how local processing works.
Questions about compress PDF for email
What size should I aim for?
Aim comfortably below the smaller applicable limit for your provider and the recipient's. Published figures often fall around 10–25 MB, but providers differ in how they count attachments and encoded messages. Include other attachments and message overhead, then check the returned PDF size. Headroom reduces the chance of a size-related rejection; it does not guarantee delivery.
My file is under the limit but the message still bounced. Why?
A provider may count the encoded message rather than just the original attachment bytes. Base64 encoding adds roughly a third, with message text and other attachments adding more. The recipient may enforce a lower limit, and delivery can fail for reasons unrelated to size. Check the bounce explanation and the relevant rules; leaving headroom addresses only some size-related causes.
Will the recipient notice the quality drop?
They may, depending on the image, small text, screen density, zoom level and print size. The fixed 110 DPI target can remove detail where downsampling is possible, and JPEG re-encoding can introduce artefacts even below that target. Check the returned file at the intended viewing size. To choose a higher resolution target, use Compress PDF; this page only exposes quality, grayscale and metadata controls.
What does metadata cleanup do before emailing?
An attachment may carry author names, software details and timestamps to current and future recipients. This toggle requests cleanup of eight standard Info keys and detaches the catalog XMP reference, but custom entries, page metadata, document IDs and detached XMP bytes may remain. Cleanup is not sanitization, and it is returned only with a smaller rewrite. An unchanged-original result retains all original metadata. Image compression is a separate, potentially lossy part of the same attempt.
Tools that pair with this one
- Compress PDFMake a PDF smaller by re-encoding its images and cleaning up its internals.
- PDF Size ReducerFor the PDF that a form, portal or mail server has just refused.
- Compress PDF for WebTry reducing a published PDF's download size without assuming every image will suit a low-resolution target.
- PDF Metadata CleanerAttempt standard metadata cleanup, with image compression still enabled and no secure-erasure guarantee.
- Split PDFCut one PDF into several documents — by range, by interval or page by page.
- Reduce PDF File SizeTry smaller image settings, then compare the returned size and appearance with your target.
Read more about this
- How to reduce PDF file size to meet a limitWritten for the case where a number is imposed on you — an email cap or an upload form. How to converge on a target quickly and what to do when you cannot reach it.6 min guide
- How to compress a PDFCompression is four independent levers, three of them lossy. This guide explains what each one does to your pages so you can choose deliberately rather than guess.6 min guide