About Convert image
Image formats each solve a different problem, and files routinely arrive in the wrong one. This converts between the three that matter on the web — JPEG, PNG and WebP — in any direction, in batches, without sending anything to a server.
JPEG is lossy and built for photographs. It has no transparency and degrades slightly every time it is re-encoded, so repeated saves of the same JPEG accumulate visible damage. It remains the most universally supported format in existence, which is why it is still the right answer for email attachments and anything opened by unpredictable software.
PNG is lossless and supports transparency. Every save produces a pixel-identical file, which makes it correct for screenshots, logos, diagrams and anything with sharp edges or flat colour. It is a poor choice for photographs — a PNG of a photograph is often several times larger than the JPEG it came from, because lossless compression has very little redundancy to exploit in camera noise.
WebP is the modern compromise: lossy or lossless, with transparency, at roughly 25–35% smaller than the equivalent JPEG or PNG. Every current browser supports it. If the destination is a website, WebP is usually the correct output and the conversion is close to free in quality terms.
What converting cannot undo. Going from JPEG to PNG does not restore detail — the information was discarded when the JPEG was first made, and the PNG simply stores the already-degraded pixels losslessly, usually at a much larger size. Converting *to* a lossless format never improves an image. It only prevents further loss from that point on.
Transparency and JPEG. Converting a transparent PNG or WebP to JPEG flattens the transparent regions onto white, since JPEG has no alpha channel. If you need transparency preserved, convert to WebP or PNG instead.
GIF and BMP inputs are accepted and converted to a still image. Animated GIFs produce only their first frame — animation is not preserved.
Questions
Are my images uploaded?
No. Conversion runs in your browser using its built-in image codecs. Nothing is transmitted.
Which format should I use for a website?
WebP, in almost every case — 25–35% smaller than JPEG or PNG at the same quality, with transparency, and supported everywhere current.
Will converting JPEG to PNG improve quality?
No. The detail was discarded when the JPEG was created. PNG will store the degraded pixels losslessly at a much larger size, with no visual gain.
What happens to transparency when I convert to JPEG?
It is flattened onto white, because JPEG has no alpha channel. Convert to WebP or PNG if transparency matters.
Does it keep animated GIFs animated?
No. Only the first frame is converted. Animation is not preserved.