Convert ico to heic
A browser can't do this one — here is what it can do.
Desktop app only
Nothing that runs in a tab can write heic from ico. This pair is waiting on the desktop build, which hands the job to the real command-line tools.
Browse what does workAbout ICO
Windows Icon
The Windows icon format, which packs several sizes of the same image, such as 16x16 and 32x32 pixels, into one file. Each size is stored as a bitmap or a PNG. Convert to ICO to make a favicon or a Windows application icon.
About HEIC
HEIC (HEVC-coded HEIF image)
HEVC-compressed images in a HEIF container. iPhones have saved photos this way by default since iOS 11 in 2017, at much smaller sizes than JPG, but Windows and many websites cannot open them without extra codecs. Convert HEIC to JPG or PNG to open iPhone photos on Windows, upload them to sites that reject HEIC, or share them.