Both PDF to JPG and PDF to PNG do the same basic job: render each page of a PDF as an image file, entirely in your browser, with no upload involved. The difference is in how JPG and PNG each store that image data, and that difference matters a lot depending on what's actually on the page. Pick wrong and you either end up with a file that's needlessly large or one that looks noticeably worse than it should.
The core difference: lossy vs. lossless
JPG uses lossy compression. It throws away some image detail -- detail your eye usually won't notice on a photo -- in exchange for a much smaller file. The more it compresses, the more that tradeoff becomes visible, especially around sharp edges and fine text, where JPG tends to produce soft, slightly blurry artifacts.
PNG uses lossless compression. Every pixel comes out exactly as it was rendered, with no quality loss, but the file is larger because there's no room to trade fidelity for size. PNG also supports transparency, though that matters less here since a PDF page rendered to an image is normally opaque.
Both LockerPDF tools use the same underlying rendering pipeline -- each page is drawn to a canvas in your browser at 2x scale for sharpness, then exported as either a JPEG or a PNG. The rendering step is identical; only the final export format differs.
Use JPG when...
- The page is a photo or has photographic content. Scanned photographs, image-heavy brochures, or pages with gradients and continuous tones compress well with JPG and the quality loss is hard to notice.
- You're sharing pages by email or messaging. Smaller file size means faster uploads, less strain on someone's data plan, and less chance of hitting an attachment size limit.
- You're converting a scanned document. If the original PDF is already a scan of a paper page, there's no crisp vector text to lose -- it's already an image, so JPG's compression is a fair trade for size.
- You need a large batch of pages and want to keep the total download small. Converting a 40-page PDF produces a ZIP of 40 images; JPG keeps that ZIP considerably smaller than PNG would.
Use PNG when...
- The page is mostly text. PNG preserves sharp, clean edges on text and fine lines, which is exactly where JPG compression artifacts show up first. A page of a report or a letter will look noticeably crisper as a PNG.
- The page has diagrams, charts, or line art. Flat colors and hard edges -- the kind you get in technical diagrams, flowcharts, or vector illustrations -- compress losslessly and cleanly in PNG, whereas JPG can introduce visible banding or blur around the edges.
- You'll edit or reuse the image later. If you're going to crop, annotate, or re-compress the image down the line, starting from a lossless PNG avoids compounding quality loss across multiple save cycles the way repeated JPG re-saves do.
- File size isn't the priority, accuracy is. Archival use cases where the image needs to be a faithful, unaltered copy of the rendered page benefit from PNG's lossless guarantee.
A quick decision guide
If you're not sure, ask what the page mostly contains. Photos, scanned paperwork, or anything you're sending to someone quickly: JPG. Text-heavy pages, diagrams, or anything you want a pixel-perfect copy of: PNG. If a single PDF has a mix of both -- some photo-heavy pages, some text-heavy pages -- you can run it through both tools and pick whichever version looks better for your specific use, since both conversions take seconds either way.
How to convert either way
- Go to PDF to JPG or PDF to PNG, depending on which format you've decided on.
- Upload your PDF -- drag it into the dropzone or click to browse.
- Click "Convert." Every page renders as a separate image in your browser.
- Download the result: a single image file if the PDF has one page, or a ZIP archive of all the page images if it has more than one.
Both conversions run entirely client-side using your browser's JavaScript engine -- your PDF is never uploaded to a server in either case.
FAQ
Which format makes a smaller file, JPG or PNG?
JPG almost always produces a smaller file because it uses lossy compression that discards some image detail. PNG's lossless compression keeps every pixel intact, which typically results in a larger file, especially for photo-heavy pages.
Does converting a PDF page to JPG or PNG upload my file anywhere?
No. Both PDF to JPG and PDF to PNG render pages using JavaScript running in your browser. Your PDF is read from your device and processed locally -- it's never sent to a server.
Will text look blurry if I convert to JPG?
It can, especially at higher compression or on pages with small text. JPG's lossy compression tends to soften sharp edges, which is most noticeable on text and line art. If a page is mostly text, PNG will generally look crisper.
Can I convert only some pages instead of the whole PDF?
Not directly -- both tools convert every page. If you only need specific pages, use the Split PDF tool first to extract those pages into their own file, then convert that smaller file.