Two questions determine which format your image needs. Does it require a transparent background? Does it contain sharp text, a logo, or line-art? If yes to either, use PNG or WebP. If no to both, use JPEG or WebP. Quality is almost never the deciding factor — and WebP, supported by every major browser since 2020, handles both use cases with smaller files than either JPEG or PNG alone.
Most format guides frame this as JPEG (lossy, smaller) versus PNG (lossless, better quality). That framing is technically accurate and practically misleading. At the sizes images are actually displayed on the web — a 1,200px blog image, a 400px product thumbnail, a 250px profile photo — a well-compressed JPEG and a PNG of the same photograph are visually indistinguishable. The quality difference exists in the data; it doesn't appear on screen at normal viewing distances.
Why JPEG produces artifacts on logos but not on photographs
Understanding why changes how you make the decision for any image, not just the ones covered by a rule list.
JPEG compression works by dividing an image into 8×8 pixel blocks and approximating the colour values across each block using a mathematical transform called the Discrete Cosine Transform. Smooth gradients — skin tones, sky, water, out-of-focus backgrounds — compress cleanly because the colour shift across those 8×8 blocks is gradual. The algorithm approximates it well.
A sharp edge does not compress cleanly. A black letter on a white background creates a sudden high-contrast transition that forces the algorithm to approximate a value it can't represent accurately across an 8×8 block. The result is the characteristic JPEG artifact: a faint halo or blur around the letter, visible at any zoom level. This is why JPEG screenshots of text look slightly soft even at high quality settings, and why a logo exported as JPEG looks worse than the same logo as PNG regardless of file size.
PNG stores every pixel exactly as it is. No approximation, no blocks, no edge smearing. That precision is what makes it the right format for text, logos, diagrams, and screenshots — not a vague claim about "better quality."
JPEG vs PNG vs WebP compared
| Use case | JPEG | PNG | WebP |
|---|---|---|---|
| Photographs | ✓ Best | Works, but large file | ✓ Best + smaller |
| Transparent background | ✗ Not supported | ✓ Best | ✓ Supported |
| Logos and flat-colour graphics | Edge artifacts visible | ✓ Best | ✓ Good |
| Screenshots containing text | Blurry text edges | ✓ Best | ✓ Good |
| File size (photographs) | Small | Large (3–5× JPEG) | Smallest |
| Browser support | Universal | Universal | All major browsers since 2020 |
When JPEG is the right choice
Any photograph without a transparent background. Hero images, product photos, headshots, landscape shots, food photography — if the image is a real-world photograph with gradual colour transitions, JPEG compresses it more efficiently than PNG with no visible quality loss at web sizes.
A photograph saved as PNG is typically 3–5× the file size of the same image as JPEG at equivalent visual quality. That extra weight slows page loads and hurts Core Web Vitals scores with no perceptible benefit to the viewer. If you need to reduce a photo for web use, our image compressor handles JPEG directly and shows the output file size before you download.
When PNG is the only option
Three situations make PNG the correct choice, regardless of file size:
- The image needs a transparent background. JPEG doesn't support alpha channels. A product photo that needs to sit on a coloured page background, or a logo overlaying a banner image, requires PNG or WebP. A JPEG will replace the transparent area with a solid colour, usually white.
- The image contains sharp text or fine line-art. Screenshots of code editors, infographics with text labels, architectural diagrams, scanned documents — anything where the eye can detect a smeared edge belongs in PNG. The degradation from JPEG is visible even at small sizes.
- Exact pixel values must be preserved. If an image will be used as a source file for further editing, or if colour accuracy is critical (a reference colour swatch, a colour-calibrated photograph for print), lossless PNG introduces no approximation into the data.
Why WebP makes this debate less relevant for most sites
WebP supports both lossy and lossless compression, handles transparency, and produces files roughly 25–35% smaller than JPEG or PNG at equivalent visual quality, according to Google's format research. Chrome, Firefox, Safari (since version 14 in 2020), and Edge all support it natively.
For a new website or a CMS migration, WebP is the practical default for both use cases: WebP lossy where you'd use JPEG, WebP lossless where you'd use PNG. The file size savings are real and the browser compatibility risk is minimal for any audience on hardware from the last four years.
The cases where JPEG and PNG remain necessary are specific: government portals and exam upload forms that mandate JPEG, stock photography platforms with format requirements, older email clients that can't render WebP inline, and legacy systems that don't accept it. In those cases, use the format the system specifies — and compress to the target size before uploading.