Gboard ‘Grammar check’ underlines are no longer exclusive to the Pixel 6

Abner Li | Feb 18 2022 - 9:57 am PT

With the Pixel 6 and 6 Pro, Google introduced a “Grammar check” capability in Gboard that “works entirely on-device to preserve privacy, detecting and suggesting corrections for grammatical errors while the user is typing.” It’s now appearing on other Pixel phones.

As you type, grammatical errors are marked by a blue underline that when tapped sees Gboard provide a complete replacement in the suggestions row. It’s enabled by default, but can be turned off on Pixel from Gboard settings > Text correction > “Grammar check.”

Mark grammatical errors with blue underlines while typing

It currently corrects English sentences and works in most Android apps, like messaging clients. Grammar check is coming to “more languages in the near future,” while corrections aren’t offered in WebView instances at the moment.

A Google AI blog post in October explained how this on-device feature was a technical accomplishment that required solving for memory size limitations, latency requirements, and handling partial sentences. It’s a privacy win that “enables users to correct their text entirely on their own device without ever needing to send their keystrokes to a remote server.”

Mobile devices are constrained by limited memory and computational power, which make it more difficult to build a high quality grammar checking system. There are a few techniques we use to build a small, efficient, and capable model.

The end result is a Grammar check model that “takes up only 20MB of storage and performs inference on 60 input characters under 22ms on the Google Pixel 6 CPU.”

Grammar check is beginning to appear on Google devices besides the Pixel 6 in recent days. It’s live on several devices we checked, running Gboard beta version 11.4, including the Pixel 5 (Android 12 and 12L) and 4a (13). We did not see it on a Samsung Android 12 or other non-Google devices today.