The short answer: use PNG for logos, icons, screenshots, and any graphic with flat colours or transparency. Use JPG for photographs and realistic imagery where file size matters. Most decisions are that straightforward. The table below covers the common cases, and the sections after it explain the one thing most format guides get wrong.
| If your image is… | Use | Why |
|---|---|---|
| A photograph | JPG | Smallest file, imperceptible quality loss at 85%+ |
| A logo or icon | PNG | Sharp edges, transparency support, no artifacts |
| A screenshot | PNG | Text stays crisp; JPG blurs fine detail |
| A graphic with text overlaid | PNG | JPG artifacts appear around high-contrast text edges |
| An ecommerce product photo | JPG | Photographic content — JPG compresses well |
| An image with a transparent background | PNG | JPG cannot store transparency — mandatory PNG |
| A hero image or blog photo | JPG | Photographic — keep file size low for page speed |
| An image going into an email | JPG | Universal email client support; PNG works but is larger |
Use PNG when you need every pixel stored exactly — logos, graphics, screenshots, and any image with transparency. Use JPG for photographs and realistic imagery. PNG is lossless: no image data is discarded. JPG is lossy: it discards detail the eye is least likely to notice, which is why a 6-megapixel JPG photograph can be under 2MB while the same image as PNG might exceed 15MB.
PNG's lossless compression works by finding repeated patterns in pixel data and encoding them efficiently — but it never throws anything away. A solid blue rectangle compresses extremely well as PNG because the pattern is simple. A photograph of a forest does not, because every pixel is slightly different from its neighbour. That's why a photographic PNG is enormous and a photographic JPG is manageable.
For graphics — logos, UI screenshots, diagrams, text-heavy images — PNG's size penalty is usually acceptable because the files are smaller to begin with, and the quality benefit is real. A JPG screenshot of a settings panel will show subtle blurring around every text character. A PNG of the same screenshot is pixel-perfect. For anything you're putting into documentation, a tutorial, or a design file, PNG is the right call.
JPEG works by dividing an image into 8×8 pixel blocks and applying a mathematical transform (the discrete cosine transform) to each block. High-frequency detail — sharp edges, fine texture — is stored with less precision than low-frequency information like broad colour gradients. At high quality settings (85–95%), the discarded detail is below the threshold of human perception for photographic content. At low settings, you see the result as blocky artifacts, particularly around sharp edges and saturated colours.
This is why photographs tolerate JPEG well and graphics don't. A photograph of a face has smooth gradients everywhere — skin, sky, clothing. JPEG's algorithm handles that gracefully. A logo with a hard black edge on white does not: the algorithm smears that sharp boundary, and the artifact is immediately visible.
The format you choose to save in matters far less than the format your file was originally saved in.
If you have a JPG photograph and convert it to PNG, the PNG will be pixel-perfect from that point forward — but it stores the exact pixels that existed in the JPG, including any compression artifacts from the original save. Converting JPG to PNG does not restore any detail that was discarded when the JPG was first created. You get a larger file with identical visual quality to the source JPG. Our JPG to PNG converter is useful for locking in a file for editing, but it doesn't undo past compression.
The more costly mistake runs the other direction. If you have a PNG — say, an original graphic or a screenshot — and you save it as JPG, then re-open it, edit it, and save as JPG again, each save introduces a new round of JPEG compression. The artifacts compound. After three or four edit-and-save cycles, quality degrades visibly even at high quality settings. This is generation loss. The fix is to keep your working file as PNG (or any lossless format) and export to JPG only as the final step for each version.
JPEG has no transparency channel. Every pixel in a JPG is a solid colour. If your image has transparent or semi-transparent areas — a logo on a clear background, a cutout product photo — you cannot use JPG without filling those areas with a solid colour.
PNG supports full alpha-channel transparency. If transparency is a requirement, PNG is your only option between the two formats. If you need to convert a transparent PNG to JPG, our PNG to JPG converter lets you choose the background fill colour before converting, so transparent areas become exactly the colour you need rather than defaulting to white.
For web use, file size affects page load speed and Core Web Vitals scores. A photographic PNG on a product page might be 8–12MB; the same image as a quality-85 JPG is typically under 500KB. That gap matters on mobile connections.
If you're working with PNG files that need to be smaller — for web, email, or upload limits — the practical options are: convert to JPG, convert to WebP (smaller than JPG at the same quality), or reduce the image dimensions. Our PNG compressor handles all three options in one place. For hitting a specific file size target in KB or MB, the main image compressor works across JPG, PNG, and WebP.
Not necessarily. At 90%+ JPEG quality, a photographic JPG is visually indistinguishable from a PNG of the same image on screen. PNG is genuinely better for graphics with sharp edges, flat colours, and text — where JPEG compression creates visible artifacts. For photographs, a high-quality JPG is appropriate and PNG would simply be a larger file with no visible quality difference.
Only if they're working files you'll edit repeatedly. Keeping them as PNG prevents generation loss from repeated JPEG saves. For final versions meant for sharing, email, or web, JPG keeps file sizes manageable without visible quality loss at high quality settings.
No. Converting JPG to PNG stores the existing pixels losslessly from that point forward, but does not recover any detail discarded during the original JPEG compression. The image looks identical to the source JPG. The benefit of converting to PNG is preventing further quality loss during future edits — not restoring past losses.
Neither PNG nor JPG has a direct SEO ranking advantage. What matters for page speed — which does influence rankings — is file size. A 400KB JPG loads faster than a 4MB PNG of the same photograph. Use descriptive alt text, keep file sizes as small as quality allows, and pick the format that gives the best quality-to-size ratio for each image.
Correct. PNG supports full alpha-channel transparency. JPEG has no transparency channel — every pixel must be a solid colour. If your image has a transparent background, PNG is required. Converting a transparent PNG to JPG fills the transparent areas with a solid colour, usually white.