PDF too large to email? Shrink it to fit

The quick fix

When your email app says the file is too large, compress the PDF and attach the smaller copy. With the NoUploadPDF compressor it takes a few seconds, in your browser, on a phone or a computer:

1. Open the compressor and choose a level. Recommended suits most emails; Smallest is for when the file must get as small as possible.
2. Choose your PDF. It is compressed on your own device, and you see how much smaller it got.
3. Download the copy, whose name ends in -compressed.pdf.
4. Attach that copy to your email, not the original.

Scanned documents shrink the most. In our tests at Recommended, our 4-page sample scan went from 9.96 MB to 563 KB, and a 6-page colour scan from 6.37 MB to 1.48 MB. A PDF of typed text shrinks less, but it is rarely the one that is too big for email in the first place.

How big an email attachment can be

The two limits most people meet:

• Gmail: up to 25 MB of attachments in one email. If you attach something bigger, Gmail offers to send it as a Google Drive link instead of a real attachment.
• Outlook.com: up to 20 MB.

Three things make the real limit tighter than those numbers suggest.

All attachments count together

The limit is for the whole email, not each file. Three PDFs of 10 MB each are too much for Gmail, even though each one alone would fit. Sending several PDFs covers what to do.

Files grow on the way

Email can only carry text, so your mail app turns each attachment into text before sending it. That makes it about a third bigger in transit, and some mail systems count the bigger size. A PDF that is just under the limit on your phone may still bounce.

The receiver has a limit too

Your email might leave your outbox fine and still be refused at the other end. Company, university and government mail systems set their own limits, and some are much lower than Gmail's. You usually can't see the receiver's limit, so the safe habit is to aim well under it. If you don't know who is receiving, keeping the whole email under 10 MB avoids most surprises.

Why not just send a cloud link? Sometimes that is the right answer, especially for very large files. But a link needs the right sharing permission, can stop working if you move or delete the file, and some people would simply rather have the file itself. For a form, an invoice or a set of scans, a real attachment is usually easier for everyone.

Which level to pick for email

Start with Recommended. It keeps pictures at up to 150 pixels per inch, which looks sharp on screens and on office printers, and the person receiving your email may well print it. Text stays exactly as sharp at every level.

Use Smallest when Recommended isn't enough, or when the file will only be read on phones. It keeps pictures at up to 100 pixels per inch. Small print in scans gets a little softer, so check it before you send.

Use Best quality for brochures, photo-heavy reports and anything that will be printed with care. It keeps up to 220 pixels per inch, so the drop is smaller, but scans made at 300 dpi still shrink.

To try another level, pick it and choose the same PDF again. Your original never changes, so you can compare the copies and attach the one you like. The level guide has a short table if you want it side by side.

Sending several PDFs in one email

Because the limit covers everything attached, several PDFs need a plan. You have three good options.

1. Compress them all, then attach them

Choose or drop all the PDFs onto the compressor at once. They are compressed one after another, and each gets its own Download button. Add up the new sizes, and if the total fits, attach them all. This keeps them as separate files, which suits a receiver who files each one in a different place, like an accounts team.

2. Merge them into one PDF, then compress

For an application or a set of supporting papers, one PDF is often neater: the receiver opens one file, in the order you chose. Join them with Merge PDF first, then compress the merged file. Merging copies every page as it is, so the merged file is about as big as the parts added together; compressing the one file afterwards is the step that makes it smaller.

3. Split the attachments across emails

If the files are still too big together, send them in two or three emails, and number the subject lines ("1 of 3", "2 of 3") so nothing gets missed.

Does putting them in a ZIP help? Not much. The pictures and text inside a PDF are already packed, so zipping a PDF rarely makes it noticeably smaller, and some mail systems are wary of ZIP attachments. Compressing the PDFs themselves works far better.

Example: emailing the papers for a loan

Say a bank asks you to email your documents for a loan: PAN and Aadhaar copies, three months of salary slips, six months of bank statements and a filled application form. Some are scans from an office scanner, some are photos from your phone, and some were downloaded from net banking. Together they come to more than Gmail allows. Here is a calm way through it:

1. Turn the photos into PDFs. Use JPG to PDF for the phone photos, with A4 pages in case they get printed.
2. Take only what was asked for. If your statement covers a whole year and they want six months, take out just those pages with Split PDF.
3. Decide: one file or several. If the bank says "attach each document separately", keep them separate. Otherwise, one merged PDF in the order of their checklist makes their job easier.
4. Compress at Recommended. The bank may print them, so keep them sharp. The scans and photos will shrink the most. The downloaded statements are mostly typed text, so they will shrink little, and that's fine: they were small to begin with.
5. Add up the sizes. If the total is still too big, compress the scans again from the originals at Smallest, or send two emails.
6. Check and rename. Open each file, zoom in on account numbers and the PAN, and give each a clear name, like Ravi-Kumar-salary-slips.pdf.

When you need an exact size

A compression level can't aim at a number. If someone tells you "send it under 2 MB", or a form on a website says "maximum 500 KB", use Resize PDF instead. You pick the size, and it makes the sharpest version that lands just under it, by trying, measuring and adjusting a few times.

In our tests in Chrome, a 42-page scan of 47.8 MB came out at 1.78 MB when we asked for 2 MB, with pictures still rated Sharp. It took 37 seconds, because each try is a full pass over a big file. Smaller files are quicker: our 9.96 MB sample came out at 445 KB for a 500 KB limit in 4.9 seconds.

Resize PDF counts 1 KB as 1,000 bytes, so a file under 500 KB there is under 500 KB however the receiving system counts. For small limits like 100 or 200 KB, which job, exam and government portals often use, see how to reduce a PDF to 100 KB.

Sharing on WhatsApp and other chat apps

Chat apps accept much larger documents than email does, so the size limit is rarely the problem. Time and mobile data are. A 10 MB scan takes a while to send on a weak signal, and the person receiving it spends their data too. A compressed copy sends faster and opens faster on their phone.

To send a PDF on WhatsApp, open the chat, tap the attach button (a paper clip on Android, a plus sign on iPhone), choose Document and pick the compressed file from Downloads on Android or from the Files app on iPhone. Sending it as a document keeps the PDF exactly as it is.

Two tips for chats:

• Smallest is usually right. The file will most likely be read on a phone, where a whole page fits on a small screen.
• Rename before sending. The receiver sees the file name in the chat. "Aadhaar-front-back.pdf" says more than "scan_0423-compressed.pdf".

The same goes for Telegram, Signal and similar apps, and for sending files by Bluetooth or a nearby-sharing feature: a smaller file moves quicker.

What the person receiving it sees

A normal PDF that opens in any PDF reader, on any device. Specifically:

• Every page, in the same order. Compressing doesn't remove pages. The engine reads the new file back to check that every page is still there, for files up to 600 MB.
• Text exactly as before. Typed text stays sharp, searchable and copyable. It is never turned into a picture.
• Pictures that look the same at normal size. Only zooming far in shows the difference, and at Recommended that difference is small.
• No watermark, no logo, no extra page. Nothing is added to show it was compressed, apart from the word in its name, so rename it.

Two exceptions are worth knowing. If your PDF had a digital signature, the compressed copy no longer carries a valid one, because the file has changed. When the receiver needs to verify the signature, as with some certificates and signed contracts, send the original or share it as a link. And if the PDF had editing restrictions, the compressed copy opens without them.

Keeping private documents private

The PDFs people most often need to email are the most personal ones: salary slips for a loan, bank statements for a visa, Aadhaar and PAN copies for KYC, medical reports for an insurer. Uploading them to a website just to make them smaller adds one more stranger's server that holds a copy.

NoUploadPDF avoids that step. The compressor runs inside your browser and saves the new file straight to your device. Nothing is sent anywhere, and you can check: once the page has loaded, switch off Wi-Fi and mobile data and it keeps working. The privacy section of the guide shows how to watch your browser's network panel while a file is compressed.

A few more habits keep private papers safer by email:

• Send only the pages that were asked for. If the bank wants the last three months, take just those pages out of a long statement with Split PDF. A smaller file is a bonus.
• Check the address twice. Autocomplete happily picks the wrong person with a similar name.
• Be careful with "anyone with the link" sharing. If a file is too big and you send a cloud link instead, share it with the receiver's address only.

If it still won't send

It is still over the limit at Smallest

If it is a long scan, Resize PDF can go further than Smallest: pick Other and type the limit in KB, like 20000 for 20 MB. If it is mostly text and fonts, which are kept as they are, send fewer pages, split it into two emails with Split PDF, or share a link.

The compressor says "Already compact"

There was nothing to gain, so you keep your original. If it is still too big for email, the fixes above are the way. Our post on reducing PDF file size covers text-heavy files in more depth.

The email app still says it is too large

Check that you attached the -compressed.pdf copy and not the original, and add up all the attachments, including pictures pasted into the email itself.

The email was sent, but it bounced back

The receiver's mail system has a lower limit. Make the file smaller, or split it across emails.

Your phone struggles with a very big scan

Phones have less memory than computers. For files over a few hundred megabytes, compress on a computer, then email it from there or move it to your phone.

The PDF needs a password to open

It can't be compressed yet. Remove the password in your PDF reader, compress the unlocked copy, and tell the receiver to expect a file without a password.

To avoid the problem next time, scan at 200 to 300 dpi, in grayscale for black-and-white papers, so your files start out small. Why is my PDF so large? explains how to scan and export smaller from the start.