Merge several PDFs into one file under 200 KB

The short answer: join first, shrink last

1. Merge your PDFs into one with Merge PDF, in the order the form lists them.
2. Shrink the joined file with Compress PDF to 200 KB.
3. Check the result before you upload: every page, every number.

The order matters. The upload limit is checked on the file you upload. If you shrink each file to 190 KB first and then join them, two of them make a file of about 380 KB, and you are over again. Shrinking last means the joined file is brought to the limit in one go.

Both tools run inside your browser, so your papers are never uploaded. The rest of this post explains each step, how many pages 200 KB can hold, and what to do when the joined file comes out too soft.

Joining the papers of an application is the subject of Combine resume, cover letter and certificates in one PDF. If you have one file to shrink and nothing to join, Compress PDF to 200 KB for online application forms is the shorter route.

Step 0: get every part as a PDF

Merge PDF joins PDF files. So each paper has to be a PDF first. These are the usual starting points:

If you photograph papers, the post Photo to PDF under 100 KB has tips on taking photos that stay clear at a small size. They apply to 200 KB too.

Step 1: merge them in the right order

Open Merge PDF and follow these steps:

1. Add your PDFs. Press Choose PDF files and pick two or more, or drop them anywhere on the page. Files that aren't PDFs are skipped with a short message.
2. Put the cards in order. Each file becomes a card showing its first page, name, page count and size. The number on a card is its place in the merged PDF. Drag the cards until the numbers match the order you want. On a phone, drag by the numbered handle in the card's corner.
3. Remove what you don't need with the X on a card. Fewer files means a lighter result.
4. Leave the bookmarks on One per file, the default, unless you know you want something else. It adds a clickable list of your documents.
5. Press Merge, then Download. The merged file is named after your first file: if class10.pdf is first, you get class10-merged.pdf.

Merge PDF copies every page exactly as it is, so nothing gets blurry at this stage. In our tests, three scans of 4, 6 and 4 pages, 23.1 MB in all, were merged into a 23.1 MB file in 0.3 seconds. The size comes out about the same as the files added together, which is why shrinking is a separate step.

A few tips for the order. If the form doesn't say, a common order is the most important document first, then the others, with the highest qualification first. Numbering your files, like 1-class10.pdf and 2-class12.pdf, often puts them in the right order from the start. Look at the first page on each card to tell similar files apart.

Step 2: bring the joined file under 200 KB

Open Compress PDF to 200 KB, choose the merged file and wait for the result. It shows the size before and after, a green "Under 200 KB" when it fits, and a word about the pictures: Sharp, Good, Readable or Rough.

The page does not stop at the first size that fits. It keeps trying, for up to six tries, until the file is within 15% under your limit, so a scan aimed at 200 KB usually comes out between 170 KB and 200 KB. A form that wants "50 KB to 200 KB" is happy with that. The new file keeps your file's name and adds -200KB, like class10-merged-200KB.pdf. Your merged file is not changed.

The page only changes the pictures in a PDF. Typed text, fonts and drawings are copied as they are. So if some of your papers are typed, such as a certificate downloaded from a portal, those pages stay sharp, and only the scanned pages give up detail.

How many pages will 200 KB hold?

Think of 200 KB as a budget that all the pages share. We measured how clear pages stay on three real scans of A4 pages at 300 dpi. Each cell shows the word the result gave and the pixels per inch (ppi) kept:

Sharp means 150 ppi or more, Good 100 or more, Readable 45 or more, and Rough anything below. All of those files came out between 166 KB and 184 KB.

The easy way to plan is to divide the limit by the number of pages. About 200 KB a page (one page) kept 131 to 159 ppi, Good or Sharp. About 100 KB a page (two pages) kept 95 to 130 ppi. About 50 KB a page (four pages) kept 70 to 99 ppi, Readable. And about 33 KB a page (six pages) kept 62 ppi for our colour report, Readable but softer.

To see how far it stretches, we joined all three of our scans into one PDF of 14 pages and 23.1 MB. It fitted: 180 KB, in 12.4 seconds, Readable at 48 ppi. That is as far as we would push it: the text could be read, but small print and the signature had suffered. A set of papers like four marksheets and a certificate is much more comfortable.

Choose what goes in, page by page

Every page you leave out gives the rest more room. Before you merge, decide on each file:

• Blank backs and cover sheets. They take part of the budget and say nothing.
• Instruction pages printed on the back of a certificate, unless the form asks for them.
• Duplicates. Two copies of the same marksheet in one file cost double.
• Long documents. Use Split PDF to take out only the pages you need before merging.

If the PDFs you have contain pages you want to rearrange between files, Organize PDF can mix pages from several PDFs, which Merge PDF doesn't do. Merge keeps each file's pages together.

If the joined file is Rough, or too soft

Rough means the pages had to drop below 45 ppi. Try these, from the one that helps most:

1. Send fewer pages, as above. Halving the pages roughly gives each page the room of twice the limit.
2. Use separate uploads, if the form has more than one slot. Then you don't merge at all: shrink each PDF on its own, and each gets its own 200 KB. In Compress PDF to 200 KB you can choose all the files at once.
3. Check whether a bigger limit is allowed. Some forms take 500 KB or 1 MB for long documents. Resize PDF lets you type any size. On our Resize PDF page, a four-page scan came out Good at 445 KB under 500 KB.
4. Start again from your first scans. A file that was already squeezed for another form has lost detail for good.
5. Crop to the paper. A page photographed on a table carries the table, and that costs part of the budget.

If the form gives you no choice and the result is Rough, it is still worth uploading once you have checked that the important numbers can be read. A soft page is accepted; a file over the limit is not.

Check the final file

• Count the pages and check the order. The compressed file has exactly the pages of the merged file.
• Check every page is upright. A sideways page can be fixed with Rotate PDF, before you shrink.
• Zoom in until the page is about as big as the real paper, and read the roll numbers, dates, marks and certificate numbers.
• Look for the stamps and signatures. They should still be visible, even if softer.
• Check the size in your file manager. "Under 200 KB" on our page means at most 200,000 bytes, which is under the limit however a website counts.

Keep your original files. If another form wants a different set or size, start again from them, not from the merged and shrunk copy.

Your papers stay on your device

A set of certificates and ID copies is private. Neither Merge PDF nor Compress PDF to 200 KB has an upload step, and neither sends your files anywhere. They run inside your browser. The page contacts only this site and Google's ad service, which shows the ads that keep the tools free, and our code never gives your files to the ad code. There is no account, no sign-up and no watermark. The privacy policy has the details.