Access keys can interfere with key mappings for browsers and assistive technologies so are best avoided.
Access keys allow users to quickly jump to specific locations of the document by pressing the corresponding key combination on their keyboard. Although this seems like a useful feature, in practice access keys cause more problems than they solve.
In particular, access keys often conflict with existing key mappings in browsers and assistive technologies. In these cases, the access key is typically ignored, leaving no value for the shortcuts. If they do override the existing mappings, though, users are unable to access the normal functionality of the combination.
Authors also need to ensure that they do not accidentally assign the same access key to more than one element. If this happens, only the first instance will be recognized.
As a rule, it is best to avoid access keys when creating content for a broad audience of users.