It changes the wrapper.
A file format is the way the same underlying media is packaged and encoded. Converting changes compatibility and storage behaviour more than it changes the subject itself.
Smart / Local Tools
Extract the portrait mask.
Turn a portrait into a clean foreground mask you can reuse for compositing, retouching or reference work.
Private by design: your selected photo stays in this browser tab. The open portrait model is downloaded from Hugging Face on first use and runs locally on your device.
Useful to know
Four things worth knowing.
Conversion is not enhancement.
Conversion is not enhancement. Re-encoding a poor source cannot restore missing detail, and some formats lose transparency, animation or metadata.
Check what the format dropped.
Automatic results still need a human check around edges, text, faces and small details.
Choose for what happens next.
Choose the format for what happens next: JPG for ordinary photos, PNG when transparency matters, WebP/AVIF for web delivery, and keep the source if you may edit again.