Codex can now use the in-app browser to test your app at different viewport sizes! It will control the device tool bar and click through your app at different breakpoints to validate & iterate. If it's a long run, Codex will take screenshots at key moments during testing and show them to you at the end of the turn, so you can verify its work. To speed up testing, Codex can hide the IAB to disable animations, and accelerate testing by 1-2x. Separately, we also made annotations send faster and consume less tokens. Hope you enjoy the updates and let us know what you think!