Image Tools guide
JPG vs PNG vs WebP vs PDF – Which Format Should You Convert To?
· 4 min read
Use JPG for photos you want to share or upload, PNG for screenshots, logos and anything with transparency or sharp text, WebP when the image is going on a website and you want the smallest file, and PDF when several images need to travel together as one printable document. Converting between them takes seconds, but picking the wrong target can cost you quality, transparency or megabytes.
This guide explains how to choose, what each conversion really does to your image, and which conversions are a waste of time.
What actually changes when you convert an image?
The pixels stay the same; the container and compression change. Every format makes a different trade-off:
| Format | Compression | Transparency | Best for | Watch out for |
|---|---|---|---|---|
| JPG | Lossy | No | Photos, email, uploads | Blurry edges on text; quality drops every time you re-save |
| PNG | Lossless | Yes | Screenshots, logos, diagrams, images you'll edit | Large files for photos |
| WebP | Lossy (with a quality setting) | Yes | Website images | Some older apps still can't open it |
| Wraps the image | — | Printing, emailing several scans as one file | Not an image format for editing |
So the real question is never "which format is best?" but "what will happen to this file next?"
A quick decision guide
Ask these three questions in order:
- Will it be printed, signed or sent as a document? Convert to PDF. Several images become one multi-page file, which is far easier for the recipient than ten loose attachments.
- Does it need transparency, crisp text or further editing? Choose PNG. It's lossless, so saving it again won't degrade it.
- Is it a photo? Choose JPG if it has to open everywhere (forms, older software, email), or WebP if it's going on your own website, where smaller files mean faster pages.
Two common real-world cases have dedicated pages: a PNG to JPG converter for shrinking screenshots and photos for upload, and a WebP to JPG converter for those "this file type is not supported" moments after saving an image from the web.
Which conversions don't help?
- JPG to PNG to "restore quality." PNG stops further loss, but it can't bring back detail that JPG compression already threw away. You'll just get a bigger file of the same picture.
- PNG to JPG for a logo with a transparent background. JPG has no transparency, so the converter fills transparent areas with white. If you need the logo on a colored background later, keep the PNG (or use WebP).
- Converting a JPG to JPG repeatedly. Each lossy save discards a little more. Edit from the original, and export once.
A worked example: the same screenshot, three ways
Say you have a 1920×1080 screenshot of a spreadsheet. As a PNG, every cell border and digit stays pixel-perfect. Save it as a JPG at a low quality and you'll see faint "halos" around the text, because JPG is designed for smooth photographic gradients, not hard edges. WebP at a high quality usually lands in between: smaller than the PNG, cleaner than a low-quality JPG.
Now flip it: a 4000×3000 vacation photo. As a PNG it can easily be several times larger than the JPG with no visible benefit, because photos contain noise that lossless compression can't squeeze. Here JPG or WebP is the obvious choice.
How to convert an image step by step
The Emojar Image Converter accepts JPG, PNG, WebP, GIF (first frame only), BMP, SVG, AVIF where your browser supports it, and PDF.
- Add your files. Drop them on the box or click to choose. You can mix types and add as many as you like.
- Pick a format in the "Convert to" menu: PNG, JPG, WebP or PDF.
- Adjust the options that appear:
- For JPG and WebP, a Quality slider (10–100%, default 90%). Around 80–90% is a good balance for photos.
- For PDF, a Page size choice: "Same as image", A4 or US Letter. A4 and Letter center each image on the page with a small margin and turn the page sideways for landscape images.
- If you added PDFs and chose an image format, a PDF resolution option: 72, 150 or 300 DPI. Each page becomes its own image.
- If you added SVGs, an SVG output width in pixels.
- Click "Convert" and download files one by one or with "Download all".
Conversion runs in your browser using its built-in image decoder, so your photos are never uploaded and the tool keeps working if your connection drops after the page loads.
Tips for better results
- Keep the original. Treat converted files as exports, not replacements.
- Combine scans in order. When converting to PDF, files become pages in the order they appear in the list, so remove and re-add any that are out of place before converting.
- Shrink as well as convert. If the goal is a smaller file, the Image Compressor adds a max-width option and shows before-and-after sizes.
- Check WebP support at the destination. Most modern browsers and apps handle WebP, but some upload forms and desktop programs still reject it.
FAQ
Can I convert an animated GIF?
Only the first frame is converted, so the result is a still image. The animation is not preserved in PNG, JPG, WebP or PDF output.
Why is my PNG bigger than the JPG I started with?
PNG stores every pixel exactly, including the compression artifacts already baked into the JPG. That's more data, not more detail. Convert to PNG only if you need lossless editing or transparency.
What happens to transparency when I convert to PDF?
Transparent PNGs are embedded as PNG, so transparent areas show the white of the page. JPGs and PNGs are placed into the PDF as they are; other formats are converted to PNG first.
Ready to switch formats? Open the Image Converter and drop in your first file.