Canon ef 40mm f 2 8 stm vs sigma 40mm f 1 4 dg hsm art?

Here is what the site says about that.

From Sigma 40mm f/1.4 DG HSM Art: Sigma 40mm f/1.4 DG HSM Art: A prime lens by Sigma for Full frame cameras, 40mm f/1.4. Specs - Maker: Sigma - Focal length: 40mm (prime) - Maximum aperture: f/1.4 - Made for: Full frame sensors - Mounts: Canon EF, Nikon F, Sony E, L-Mount - Stabilised: no - Autofocus: yes What it frames like - On full frame (Canon EF, Nikon F, Sony E, L-Mount): as marked, 40mm. - On APS-C (Nikon F, Sony E, ...

From Canon EF 40mm f/2.8 STM: Canon EF 40mm f/2.8 STM: A prime lens by Canon for Full frame cameras, 40mm f/2.8. Specs - Maker: Canon - Focal length: 40mm (prime) - Maximum aperture: f/2.8 - Made for: Full frame sensors - Mounts: Canon EF - Stabilised: no - Autofocus: yes What it frames like - On full frame (Canon EF): as marked, 40mm. - On APS-C (Canon) (Canon EF): like 64mm on full frame; f/2.8 gives about the depth of ...

Quoted from this site's pages.