Image formats · 7 minute read
JPEG vs PNG vs WebP: which image format should you choose?
There is no single best image format. JPEG, PNG and WebP make different trade-offs, so the right choice depends on the image content, transparency, compatibility and whether the output may discard visual information.
Use JPEG when photographic size matters most
JPEG uses lossy compression and is widely suited to photographs and other continuous-tone images. Lower quality settings can reduce the file substantially, but repeated re-encoding and aggressive compression can introduce visible blocking, ringing and softened detail.
JPEG does not preserve an alpha transparency channel. Transparent source pixels need a chosen background colour when exporting to JPEG.
Use PNG for transparency and exact hard-edged graphics
PNG provides lossless compression and supports alpha transparency. It is a strong choice for interface graphics, diagrams, screenshots and artwork where sharp edges or exact pixel values matter.
Lossless storage can make photographic PNG files much larger than a suitable lossy alternative. Converting a camera photograph to PNG does not restore information already lost in an earlier JPEG.
Use WebP when you want modern compression flexibility
WebP supports both lossy and lossless compression as well as transparency. It can be a practical web-delivery format when smaller assets matter and the target browsers or applications support the workflow.
Compatibility is broader than it once was, but a downstream editor, content-management system or customer process may still impose a JPEG or PNG requirement. Test the real destination rather than relying only on browser support.
Convert from the best available source and inspect the result
Keep the original source file, resize to the actual required dimensions and compare candidate exports at the display size that matters. File extension, quality setting and pixel dimensions all affect delivery weight.
Browser canvas conversion flattens animation to a still frame and the current 4g3n7 workflow does not preserve source EXIF metadata. Check important artwork visually and do not discard the original when capture time, location, colour-management data or provenance matters.
- Photograph: compare JPEG and lossy WebP
- Logo with transparency: compare PNG and lossless WebP
- Screenshot or diagram: begin with PNG or lossless WebP
- Required legacy workflow: use the format the receiving system explicitly accepts
Verify what the browser actually exported
Canvas export quality controls apply to lossy encoders such as JPEG and WebP; PNG is lossless, so the same slider does not mean the same thing. A quality value is encoder-specific—it is not a promise that a fixed percentage of bytes or visual information remains.
When a requested canvas export type is unsupported, the browser can silently fall back to PNG. Check the downloaded MIME type, dimensions and actual file size instead of assuming that a “compressed” re-encode is smaller or uses the requested format.