PDF to JPG slow or too big? Why, and how to fix it

What you see, and where to look

PDF to JPG draws each page one at a time in your browser and saves it as a picture. Most problems come from the number of pages, the sharpness you chose, or a phone's limited memory. Find yours:

It is slow, or seems stuck

Time depends on the number of pages and on what is on them. Scans take the longest, because each page is a big photo that has to be unpacked before it can be drawn. Pages of text are quicker. Here are real times from our own tests, run in headless Chromium at computer size. A phone may be slower, and these tests don't cover Safari or Firefox:

The time grows with the number of pages. So the biggest savings come from asking for fewer pages or less sharpness:

1. Convert only the pages you need. Tap Choose pages and type them, like 1-3, 5. The button counts the pages, so you can check before you start.
2. Choose Normal instead of High. Normal (150 ppi) is sharp on phones, screens, slides and most forms. High has four times the pixels, and in our tests its files were 2.4 to 4.3 times bigger.
3. Use the progress line. While it works, the page shows how far it has got, like Page 3 of 12. If you see it moving, wait.
4. Press Stop if you need to. The pictures made so far are kept, and you can download them.

The pictures add up to more than the PDF

This surprises many people. A PDF of typed pages is small because it stores letters, not dots. A picture of a page has to store every dot. A scan is different: it is already pictures, and the JPGs can come out smaller. These are our measured examples at Normal sharpness:

So a typed document grows when it becomes pictures, and a scan shrinks. If your pictures are too big:

• Choose Small (72 ppi) for the smallest files. The 14-page paper came to 2.06 MB at Small. Small print can be hard to read at this size.
• Convert fewer pages. Only the pages you'll use.
• Ask whether you need pictures at all. If someone only wants to read the document, send the PDF itself, or make the PDF smaller with the PDF compressor. A picture keeps how the text looks, not the text itself, so it can't be searched or copied.
• For a form's limit in KB, choose Small and convert only the page you need. The pages of our sample scan came out at 60 to 70 KB each at Small and 396 to 422 KB at Normal. Convert PDF to JPG for form upload goes through it.

It stalls or stops on a phone

Phones have less memory than computers, so the converter draws one page at a time and keeps only the finished picture files. That lets long PDFs work, but a few habits help a lot:

• Keep the page open, in front, with the screen on. Browsers slow down or pause pages you aren't looking at. If you switch to another app while it works, it may stop making progress until you come back.
• Convert a long PDF in parts, like 1-50 and then 51-100. Each part is a separate run and a separate ZIP.
• Close other tabs and apps before a long run.
• Use Normal, not High, for long files. On an iPhone or iPad, one picture can have up to 16 million pixels (40 million on a computer). A very big page, like an A1 poster, is drawn at a lower ppi to fit: at High it comes out at 144 ppi on an iPhone and 227 ppi on a computer. The result tells you when this happens.
• For a very long file, try a computer. We converted all 400 pages of a 454.8 MB scan in one go on a computer, and it took 135.6 seconds.

A phone may be slower than our test computer. If a run seems to take long, check that the progress line is still moving before you start over.

ZIP files, and finding your pictures

One page gives one picture with its own Download button. Several pages come in a ZIP file, which is one file that holds many. It is named after the PDF, like marksheet-jpg.zip. With several PDFs it is called pdf-to-jpg-3-files.zip for 3 PDFs. JPG files are already compressed, so the ZIP is about as big as the pictures together. To open it:

• Android: open your Files app (Files by Google, or My Files on Samsung phones), tap the ZIP file, then tap Extract.
• iPhone and iPad: in the Files app, tap the ZIP file. A folder with the pictures appears next to it. To add a picture to Photos, open it there, tap Share, then Save Image.
• Windows: right-click the ZIP file and choose Extract All. Mac: double-click it.

Only need one or two pictures? Skip the ZIP and use the Download button under each picture's preview. If the download didn't show up, look in your Downloads folder, or in Downloads in the Files app on an iPhone. If it isn't there, press the Download button again: your pictures stay ready until you change something or leave the page. A ZIP file can hold up to 4 GB. Above that, the result asks you to download the pictures one by one.

The pictures are named after the PDF and the page: marksheet-page-1.jpg. From 10 pages up, the numbers get zeros in front, like report-page-01.jpg, so they sort in page order.

Soft text, a sideways page or a missing page

Text looks soft.

Choose High and convert again. If the PDF is a scan, the pictures can only be as sharp as the scan. Choosing more ppi than the scanner caught makes bigger pictures, not sharper ones.

A picture is sideways.

The page is sideways in the PDF too: each picture shows its page the way the PDF shows it. Turn the picture in your gallery or photo editor, or fix the PDF first with Rotate PDF.

A page is missing from the result.

If a page can't be drawn, it is left out and the result says which one. The other pages are still converted. Try that page again on its own.

A page past the end.

With a 4-page PDF, "2, 9" gives page 2 and a note that page 9 was skipped.

I wanted a see-through background.

Pages are drawn on white, like paper, so see-through parts are not kept, even in PNG. See PDF to PNG with no background.

It asks for a password, or can't be opened

• It asks for a password. The PDF is locked. Type the password on its card and press Open. It is used only on your device. Until then, the PDF is left out, and your other PDFs are converted without it.
• "Can't be opened: it may be damaged, or not a PDF." The file may be broken, cut short while downloading, or another kind of file with a .pdf name. Try opening it in a PDF reader. If that works, save or print it as a new PDF there, and add the new copy.
• Forgot the password? There is no way around it here. The tool never guesses a password. PDF says wrong password? What to check lists the usual causes.

A short routine that avoids most trouble

1. Decide which pages you need, and type them under Choose pages.
2. Pick the sharpness for the use: Small for tight limits, Normal for screens and forms, High for printing and cropping.
3. Press Convert. Check that the button counts the pages you expect.
4. Keep the page open and in front until the pictures appear.
5. Look at the size under each picture, and open one to check the smallest text.

If you change the sharpness, the format, the pages or the PDFs afterwards, the pictures are cleared and the Convert button comes back, so what you download always matches what you chose. Keep your PDF too, as a picture can't be searched or copied.

Your PDF is never sent while you try again

PDF to JPG has no upload step. The pages are drawn by pdf.js inside your browser, so your PDF and its pictures never leave your phone or computer. 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. The privacy policy has the details.