How do I make a PDF smaller to email it?

Open Kopitiam's Compress PDF, choose Shrink photos for documents with pictures or Strong for scans, and click Compress PDF. Check the new size against your email limit, then download. It runs in your browser, so the file is never uploaded.

Which compression mode should I use?

Lossless for text documents, Shrink photos for documents with photos, and Strong for scanned pages. Lossless and Shrink photos keep text selectable. Strong gives the biggest savings but turns pages into pictures.

Why did compressing barely change my PDF?

Your PDF is probably mostly text, or its images aren't stored as JPEG photos. Text is already compact, so there's little to remove. If it's a scan, try Strong.

Will compressing a PDF ruin the quality?

Lossless doesn't change how anything looks. Shrink photos and Strong lower image detail, which is rarely noticeable on screen or in normal printing. Zoom in on the smallest text after compressing to make sure it's still readable.

Can I keep the text selectable after compressing?

Yes, with Lossless or Shrink photos. Strong is the only mode that turns pages into pictures, so its text can't be selected or searched.

What size limit do email attachments have?

It depends on the provider. Many personal email services allow around 20 to 25 MB, and work email is often lower. Leave some headroom, because attachments grow by about a third when sent.

How to make a PDF smaller to email (free, no upload)

To make a PDF small enough to email, open Kopitiam's Compress PDF, pick a mode, click Compress PDF and check the new size before you download. Pick Shrink photos for documents with pictures, Strong for scanned pages, and Lossless for plain text documents.

Which mode you pick matters more than anything else. A scan can drop to a fraction of its size, while a text-only PDF may hardly change at all. It is free, there's no account, and the file is compressed inside your browser, so it is never uploaded.

How big can an email attachment be?

There is no single rule, but many personal email services cap attachments at around 20 to 25 MB. Work email is often set lower by the company, sometimes 10 MB. Online forms and government portals can be stricter still, sometimes only a few megabytes per file.

Aim below the limit, not at it. Attachments grow by roughly a third when they are encoded for sending, so a 20 MB file can count as more than 25 MB.
The recipient's limit matters too. Your provider may send a large file that their server then rejects.
Some services offer to turn a large attachment into a cloud link instead. That works, but the file then sits on that service.

Why your PDF is so big

Text is tiny. A 30-page text-only report is often well under 1 MB. Pictures are what make a PDF heavy: scanned pages, phone photos and high-resolution images inserted from a camera.

A phone or office scanner set to high resolution and colour can produce several megabytes per page. A 12-page tenancy agreement scanned that way can easily reach 40 MB, even though it is only text on paper. That is good news, because image-heavy files are exactly the ones that compress well.

How to compress a PDF, step by step

Open Compress PDF and drop your file onto the page, or click to choose it.
Under Compression, choose Lossless, Shrink photos or Strong. The next section explains which.
If you chose Strong, also pick a quality: Higher quality, Balanced or Smallest.
Click Compress PDF. You'll see the original size, the new size and how much smaller it is.
Click Download compressed PDF. The copy is saved with "-compressed" added to its name, and your original is unchanged.
Open the compressed copy and read a page of small print before sending it. If it's not legible, try a gentler setting.

You can try another mode on the same file straight away. Choose a different option and click Compress PDF again; each run starts from your original, not from the last result.

The three modes, and what to expect from each

Lossless re-saves the PDF in a more compact structure and clears document details such as the title and author fields. Pictures are not touched and text stays selectable. Savings are usually modest. It suits CVs, letters and reports that are mostly text, but it won't rescue a 40 MB scan.

Shrink photos does everything Lossless does, then makes the JPEG photos inside the PDF smaller. Photos larger than 1,600 pixels on their longest side are scaled down, which is still plenty for reading on screen or printing at normal size, and re-saved at a lower JPEG quality. A photo is only replaced if the new version is clearly smaller. Text, lines and layout are untouched, so text stays selectable.

Shrink photos works best on documents with big camera photos: a property listing, an inspection report or a school project with pictures. It barely changes PDFs whose images are stored another way. That includes many charts and screenshots, images prepared for professional printing, and black-and-white scans from office scanners. If nothing could be made smaller, Kopitiam says so and suggests Strong for scanned pages.

Strong turns each page into a single JPEG picture and builds a new PDF from those pictures, keeping the original page size. It gives the biggest savings on scanned documents, because a scan is already a picture of each page. Higher quality draws pages at about 200 DPI on an A4 page, Balanced at about 150 DPI and Smallest at about 120 DPI. Start with Balanced.

Strong turns every page into a picture. Text in the compressed copy can no longer be selected, searched or copied, and links and fillable form fields stop working. Use it for scans, keep your original, and don't use it on a document someone needs to search or fill in.

On a text-only PDF, Strong can make the file bigger, since a picture of a page is larger than the text that describes it. Kopitiam never hands you a bigger file. If any mode would make the file larger, it shows the size, explains why and offers no download, because your original is already the smaller one.

Two worked examples

A 40 MB scanned tenancy agreement for a 25 MB email limit. Lossless and Shrink photos may do little here, depending on how the scanner saved the pages. Strong at Balanced usually gives the big cut you need, and the before and after sizes tell you the real result. Zoom in on the small print, the IC numbers and the stamp to check they are still clear. If they are, send it. If the file is still too big, try Smallest and check again.

An 18 MB property report full of phone photos. Use Shrink photos. The photos get smaller, and the text, prices and addresses stay selectable for the buyer. Strong would make it smaller still, but the text would turn into pictures, which is a poor trade for a document people will search and copy from.

If it's still too big

Send fewer pages. Use Extract Pages to send only what was asked for, or Organize PDF to delete blank pages and duplicates.
Split it. Split PDF cuts the file into parts you can send in two or three emails. Label them part 1 of 2 and part 2 of 2 so nothing gets missed.
Rescan at a lower setting next time. Greyscale at 150 to 200 DPI is enough for most paperwork and produces far smaller files than colour at high resolution.
Share a link. For very large files, a cloud storage link is often simpler than any attachment.

Things to know before you compress

Password-protected PDFs can't be opened yet. Open the file with its password in your PDF reader, use Print and then Save as PDF to make an unlocked copy, and compress that.
PDFs with editing restrictions can't be changed either. The same Print to PDF trick works.
A digitally signed PDF will no longer show a valid signature after compressing, because the file has changed. If the recipient needs to verify the signature, send the signed original or share it by link.
On a phone, Strong redraws every page, so a long scan can take a while and use a lot of memory. Kopitiam sets no file-size limit; the practical limit is your device's memory.

Once the page has loaded, compression keeps working even if your connection drops. Your file stays on your device the whole time, which is worth a lot when the document is a payslip, an IC copy or a signed contract.