Convert the file, not just its name.
Changing image.png to image.jpg does not change its contents. This tool decodes the image and creates a new file whose actual MIME type is checked. A transparent PNG sent to JPEG needs a background.
Know what this tool supports.
Static PNG, JPEG and WebP only. Animated PNG/WebP, GIF, HEIC, SVG and PDF are rejected rather than silently simplified. Very large files are limited before decoding where their headers can be read. A malformed image can still fail decoding. JPEG orientation is handled by the browser; compare the preview.
Does this upload my image?
No. Reading, rendering and encoding happen in this tab. The site makes no file-content requests, does not use analytics and does not persist images. See Privacy for page-request limitations.
Will the result look exactly the same?
Not necessarily. Lossy output, resizing, cropping, color management and re-encoding can change appearance or metadata. Keep the source and inspect the copy. Do not use this workflow when exact source bytes or metadata must be preserved.
Why can a smaller-looking picture still be a large file?
Pixels describe dimensions; bytes depend on content, format and encoder settings. Read the size guide before choosing resize or compression.
Can this certify an application photo?
No. Even the checker compares only technical properties with the rules you enter. It does not verify identity, facial position, lighting, background acceptability or changing destination policies.