JPG vs PNG vs WebP: Which Image Format Should You Actually Use?
Most people pick an image format out of habit — JPG because that's what the camera saved, PNG because it "looks safer." The three formats actually solve different problems, and picking the wrong one either bloats your file size or wrecks your image quality. Here's the practical version, without the codec theory.
The short answer
If you only remember one table, remember this one:
| Format | Best for | Avoid for | Transparency |
|---|---|---|---|
| JPG | Photos, complex images with lots of colors and gradients | Logos, text, screenshots, line art | No |
| PNG | Logos, screenshots, graphics with sharp edges or text, anything needing a transparent background | Large photos (file size gets big fast) | Yes |
| WebP | Almost everything on the web — photos and graphics, smaller than both JPG and PNG at similar quality | Old email clients, some design software that doesn't open it | Yes |
The rest of this guide is really just explaining why that table looks the way it does.
JPG: built for photos, and only photos
JPG uses "lossy" compression — it throws away image data that the human eye is less likely to notice, which is why a JPG photo can be a fraction of the size of the same image saved losslessly. This works beautifully on photographs because photos are full of smooth color gradients and subtle noise that compress well without looking obviously different.
It falls apart on anything with sharp, high-contrast edges: text, logos, icons, or a screenshot of a spreadsheet. JPG compression creates a fuzzy halo (called "ringing") around hard edges, and text in particular ends up looking smudged. If you've ever saved a screenshot as JPG and noticed the text looks slightly blurry compared to the original, that's exactly what's happening.
JPG also has no transparency support — the background is always a solid color, never see-through. And every time you re-save a JPG (edit it, then save again, then edit again), it loses a little more quality, since the compression is applied fresh each time. A JPG that's been re-saved a dozen times over the years usually looks noticeably worse than the original.
PNG: the format for anything that isn't a photo
PNG uses lossless compression — nothing is thrown away, so the file looks pixel-for-pixel identical to the original no matter how many times you re-save it. That makes it the right choice for logos, icons, screenshots, diagrams, and any graphic where sharp edges and exact colors matter.
PNG is also the format to reach for whenever you need a transparent background — a logo that needs to sit on top of different colored backgrounds, a product photo with the background removed, or an icon meant to overlay other content. If you're starting from a photo with a solid background and need it gone, a tool like CalcPerch's Background Remover handles that, and the result should be saved as PNG (or WebP) to keep the transparency — saving it as JPG afterward would just fill the transparent area with white.
The tradeoff is file size. Because nothing is discarded, a PNG of a detailed photo can be five to ten times larger than the same image saved as JPG, with no visible quality benefit for that particular use case. Using PNG for photographs is one of the most common and most avoidable causes of a bloated, slow-loading website.
WebP: the newer format that usually wins
WebP was built by Google specifically to beat both JPG and PNG at their own games — it supports both lossy compression (like JPG, for photos) and lossless compression with transparency (like PNG, for graphics), typically producing files 25-35% smaller than the equivalent JPG or PNG at comparable visual quality.
Browser support has been essentially universal for years now — every major browser (Chrome, Firefox, Safari, Edge) renders WebP natively, so for websites there's rarely a reason not to use it. The situations where WebP still causes friction are outside the browser: some older design tools, some email clients, and some social platforms don't handle it cleanly, and a handful of people will still occasionally hit a "this image can't be opened" error if they try to open a WebP file in an older program.
Real situations, and which format actually fits
- Uploading photos to a blog post. WebP if your platform supports it (most modern CMSs do); otherwise a compressed JPG. Never PNG for photos — the file size penalty isn't worth it.
- A logo for your website header. PNG or WebP with transparency, never JPG — a JPG logo will always have a visible box around it instead of blending into the page background.
- A screenshot for a tutorial or support ticket. PNG. The text and UI elements stay crisp, and screenshots compress well as PNG anyway since they have large areas of flat color.
- Product photos for an online store. JPG or WebP — these are photographs, and shoppers care more about fast page loads than lossless pixel accuracy.
- An image you'll edit repeatedly over time. Keep a lossless master (PNG, or your editor's native format) and export a compressed JPG/WebP copy only for the final use — that way repeated edits don't compound quality loss.
Converting and compressing without guessing
Once you know which format you want, the actual conversion is the easy part. CalcPerch's Image Converter switches between JPG, PNG, WebP, and HEIC (the format iPhones save photos in by default) entirely in your browser — nothing gets uploaded to a server, which matters if the images contain anything personal.
File size is a separate lever from format. Even after picking the right format, a photo straight off a phone or camera is often needlessly large for web use — CalcPerch's Image Compressor reduces file size by adjusting quality and dimensions without a visible difference at normal viewing sizes, which is usually the bigger win for page-load speed than format choice alone. The two work together: pick the right format first, then compress within it.
A rule of thumb that avoids most mistakes: if the image came from a camera or phone, treat it as a photo (JPG/WebP). If it was made in a design tool, has text, or needs a transparent background, treat it as a graphic (PNG/WebP). WebP quietly covers both cases if you're not sure your target platform will accept it — check first, since a handful of upload forms still reject it.
Frequently asked questions
Is WebP always better than JPG and PNG?
For file size and browser use, almost always — WebP typically produces smaller files than JPG or PNG at similar visual quality, and support in browsers is universal. The exceptions are specific tools or platforms that don't accept WebP uploads, or if you need maximum compatibility with very old software.
Why does my PNG file look huge compared to my JPG of the same photo?
PNG is lossless — it keeps every pixel of detail, which is great for graphics but means photographs (full of subtle color variation) compress far less efficiently than they would with JPG's lossy approach. If the image is a photograph rather than a graphic, switching it to JPG or WebP will usually shrink it dramatically with no visible quality loss.
Can I convert a JPG to PNG to get transparency?
No — converting a JPG to PNG changes the file format but can't add transparency that was never there, since JPG has no transparent pixels to begin with. To get a transparent background, you need to actually remove the background from the image first (with a background-removal tool), then save the result as PNG or WebP.