PNG or JPG for a PDF page? Pick by where it is going

The short answer: PNG for typed pages, JPG for scans

Pick PNG for typed or drawn pages and JPG for scanned or photographed ones. Where the picture is going can change the answer a little, so here is the whole thing in one table. The sizes are what the page showed when we converted one page at Normal (150 ppi) in both formats, in Chromium 141 (the browser Chrome is built on) on a computer:

The pattern is easy to see. On pages of letters and lines, one page as a PNG was at most a few tens of KB bigger than the JPG, and the fax-like page was smaller, so PNG's exact edges cost very little. On scans and photos, PNG was three and a half to twelve times bigger in our tests, with no difference you could see.

Not sure which row your page belongs in? The next part shows how to tell, and a one-minute test settles it for any page.

First question: is your page typed, or a picture of paper?

A PDF can hold two very different things. A typed page was made on a computer: a resume saved from Word, a downloaded bank statement, a school notice, an e-ticket. It is stored as letters and lines. A scanned page is a photograph of paper: a marksheet scanned with a phone app, a photographed certificate.

This is what decides the format. PNG keeps every pixel with no loss, and it packs flat areas very well. A typed page is mostly flat white with sharp black letters, so PNG suits it. A scan is full of fine grain from the paper, the ink and the light. PNG keeps every grain exactly, and that is why scan PNGs get huge. JPG is built to leave out tiny details the eye hardly notices, which is a good trade for grain. At the quality we use, letters in a JPG stay as crisp as in a PNG at normal zoom. Our guide shows the page-by-page table behind this.

How to tell which you have

Open the PDF in any reader and try to select a word with your finger or mouse. If it highlights, the text is real, so the page is typed. If nothing highlights, it is most likely a scan. Zooming in far also shows it: real text stays smooth, scanned text turns blocky or fuzzy.

Pages that are both

Brochures, wedding invitations, resumes with a photo, price lists and school magazine pages mix text and pictures. The more of the page is photo, the more PNG costs. A page with a large colour photo was 889 KB as a PNG and 74 KB as a JPG. On a page that mixes the two, the PNG's size falls somewhere between the typed rows and the photo row. We did not measure every mix, so test yours.

The black-and-white scan is the exception

A page of pure black text on white, like a fax or a scan made in the scanner's black-and-white mode, is a scan that prefers PNG. Our fax-like page was 280 KB as a PNG and 385 KB as a JPG, so the PNG was 27% smaller. JPG handles hard black edges on white badly. So "scan" does not always mean "JPG". When in doubt, test.

WhatsApp and other chats: send it as a photo or a document?

For a chat, how you send the picture decides whether your choice of format even reaches the other person. WhatsApp and other chat apps often turn a picture sent as a photo into a smaller JPG, to save data. So a PNG sent as a photo usually arrives as a squeezed JPG anyway, and small print can blur. Picking PNG only pays off when you send it as a file. You have two ways to send:

• As a document, to keep it exactly as it is. Use the attach button and choose Document instead of the photo option. The other person taps it to open it. This is best for a timetable, a price list or a form where small print counts.
• As a photo, for a quick look. It shows right inside the chat with no tap, which is handy for a notice everybody just needs to glance at. Here the format you picked matters less, because the app makes its own copy. JPG is the lighter start.

Some more points that help in a chat:

• Mind the data. One page of our colour scan was 422 KB as a JPG and 2.85 MB as a PNG. Send four such pages as PNGs and you spend a lot of mobile data, and so does everyone in the group who downloads them. Typed pages are small either way: our form was 70 KB as a PNG.
• Use Normal, not High. Normal is right for screens: text is crisp on a phone and a laptop. High only makes the file bigger, and the extra pixels only show when someone zooms in a lot.
• Several pages? Skip the ZIP. Under each picture is its own Download button. Chat needs pictures, and a ZIP file has to be unpacked by the other person. The names sort in page order, like report-page-01.png, report-page-02.png (the zeros appear from 10 pages up). Send them in that order.
• Only part of the page matters? Small print on a whole A4 page is hard to read on a phone. Convert that page at High and crop the part you want in your gallery. A quarter of a High page has as many pixels as a whole page at Normal, so it stays sharp. Our article on how many pixels each job needs has the sums.

Why not send the PDF? A picture opens inside the chat. A PDF has to be downloaded and opened first. But a PDF keeps its text, so the other person can search and copy it. If they need to do that, or to print many pages, send the PDF. A picture is for "have a look at this".

Instagram and other social apps

Instagram, Facebook and other social apps usually save your upload again in their own way, often as a smaller file, to save space. So you don't control the final format, and a PNG may not stay a PNG on the way. What you do control is what you start with: sharp, in the right shape, and not too big.

• Shape. Each picture has the shape of its page. A full A4 page is taller than an Instagram feed post can be, so you will need to crop it. Stories and statuses take the shape of a phone screen, which is narrower for its height than A4, so a whole page fits with bands of space above and below it. If you designed the PDF yourself and gave it a square or tall post shape, your pictures keep that shape and nothing needs cropping.
• Several pictures in one post. Use Choose pages and type the pages you want, like 1-5. Add the pictures to your post in page order.
• One idea per picture. The text of a whole page is tiny on a phone. Crop the part that matters from a High picture, so it fills the screen and stays sharp.
• Which format. For text, charts and graphic pages, PNG is a good start, because the edges are crisp before the app shrinks the picture. For a page that is mostly a photo, use JPG: a PNG would only be a bigger upload (889 KB against 74 KB in our test).
• The background is white. Every page is drawn on white, like paper. A flyer with no background of its own shows as a white page.

Normal is enough for a phone screen. Choose High only when you plan to crop. Our article about converting PDF to PNG in high resolution explains when the extra pixels pay off.

PowerPoint, Google Slides, Keynote and Canva

All four take PNGs, and PNG is the safe choice for most of what people paste into slides: charts, tables, diagrams and typed pages. Edges stay crisp when the slide is shown on a big screen, with no fuzz around bars and labels.

• A slide is wide, a page is tall. Slides are usually wide, so a whole upright page fills only a narrow strip down the middle. Most of the time you want one part of it, like a chart. Convert at High, then crop the picture inside the slide program or in a photo editor. A crop a quarter of the page in size (half as wide and half as tall) still has as many pixels as a whole page at Normal.
• If your PDF is itself a slide deck, every page is wide, and each picture comes out wide too, because sideways pages stay sideways. Normal is enough.
• One picture per slide. The names keep page order, so insert them one by one in name order.
• Dark slides. Each page is a white picture. On a dark theme it looks like a hole in the slide, so put it on a white box or give it a thin border. See-through parts are not kept, so a logo or signature will not come out with a clear background. The guide shows how to cut one out.
• Watch the deck's size. Every picture adds to the file. The 14-page research paper came to 7.9 MB as PNGs at Normal and 20.0 MB at High. Convert only the pages you will show.
• Photo pages are better as JPG, which keeps the deck lighter.

A picture's words can't be changed. If a number in a table is wrong, you can't fix it inside the PNG, and nobody can search or copy it. When you need the words themselves, PDF to Word turns a PDF into a Word file you can edit. It works best on PDFs with real text. A scanned page there stays a picture, because the tool does not read scans as text.

A screenshot is still the quickest way to grab one small part for a slide you are making right now. Zoom in first so that the part fills the screen. For whole pages, converting is sharper, as the guide shows in convert, or just take a screenshot.

Upload forms, Word files and print shops

Upload forms with a size limit

Job, exam and college portals often want a certificate as an image under 100 KB or 200 KB. Start with JPG. Our page of a scan was far over those limits as a PNG at every sharpness. This tool can't aim at an exact file size for a picture. Switch Format to JPG, choose Small (the tool's own hint suggests it for size limits), convert only the page the form asks for, and read the size shown under the picture. Text can be hard to read at Small, so check the picture before you upload it. If the portal also accepts a PDF, Resize PDF can make a PDF fit under a limit you pick.

Word documents

Each PNG carries its ppi, so Word and printers should treat it as the size of the page. Insert the picture, then shrink it to fit. Normal is enough.

Print shops and designers

Ask what the shop wants. If it asks for 300 DPI, choose High. Many print shops accept a PDF as it is, and a typed PDF stays sharp at any print size, so a picture may not be needed. If a designer is placing the page in a layout, give them PNG: colours and edges stay exact until they make the final file.

Settle it in a minute: make both

When you can't tell which format suits your page, let the tool show you. It takes one page and two conversions:

1. Open PDF to PNG and add your PDF.
2. Tap Choose pages and type a page or two that look typical, like 3, 8. Include a heavy one, such as a page with a photo, if you have it.
3. Leave the sharpness on Normal and tap Convert. Note the size shown under each picture, and tap Download to keep the PNG.
4. Under Format, tap JPG. The PNG is cleared from the page (the one you downloaded stays on your device) and the Convert button comes back. Tap Convert again and note the new size. (This is the same tool as PDF to JPG, with JPG chosen.)
5. Look at both. Open the PNG you saved and the new JPG, and zoom in on the smallest print. If you can't see a difference, take the smaller file. If the JPG shows a haze around letters you care about, take the PNG.
6. Convert the rest of the pages the same way.

A difference of a few tens of KB doesn't matter. A difference of megabytes does.

Mix-ups to avoid

• "PNG means better quality than the PDF." No. A picture has a fixed number of pixels, while a typed PDF stays sharp however far you zoom. PNG only promises that nothing is lost from the pixels you chose.
• "PNG means see-through." It can, but pages made here are always drawn on white, so they never are.
• Sending a scan as PNG. Scans are where PNG files get huge. Switch Format to JPG.
• Editing JPG again and again. Each time a JPG is edited and saved, it loses a little more. Edit the PNG, and save a JPG only as the last step if you need a small file.
• Throwing the PDF away. A picture shows how the text looks, not the text, so it can't be searched or copied, and links and form fields don't work in it. Keep the PDF.
• Using High for a chat. The extra pixels never show on a phone, and the file is always bigger: almost four times bigger for our sample scan.

Need a PDF again later? PNG to PDF puts PNGs made here back into a PDF, and JPG to PDF does the same for JPGs. And nothing in this article needed an upload: the pages are drawn in your own browser, so your documents stay on your phone or computer.