Pick the output format for the next step.
JPEG is widely accepted by forms and document software and works well for photos. PNG keeps pixels without JPEG-style loss and supports transparency, but a photographic PNG can be much larger. WebP supports transparency and efficient compression, though some older portals do not accept it. The converter checks the actual MIME type produced by the browser rather than giving a PNG file a misleading WebP extension.
HEIC conversion is about compatibility, not guaranteed compression.
An iPhone HEIC photo may need conversion before a website or another device can open it. This tool uses a browser-side decoder and exports the first still image. HEIC sequences, depth information, animation, and all original camera metadata are not preserved. Some HEIC variants cannot be decoded by this library; an error does not prove that the original photo is corrupt. Keep the original file.
Changing format can make the file larger.
A new file format is not automatically smaller. An efficient HEIC or WebP photo converted to JPEG or PNG can increase in size. The result reports both original and output sizes so you can choose deliberately. If a strict upload limit matters, use the compressor afterward. Converting a low-quality JPEG to PNG does not restore detail already lost in the JPEG.
Review transparency and rotation in the exported file.
Transparent pixels become white when exported as JPEG. Browser image decoding generally honors common image orientation, but unusual camera encodings may differ. Open a downloaded example before sharing an entire batch. Each output is re-encoded as a fresh still image; do not use this workflow when preserving embedded metadata or all frames is a requirement.