Chrome requires about 20GB free

Google’s Chrome documentation now makes the storage cost of its on-device AI more explicit. Chrome’s built-in AI features rely on a local model download, and Google says that download only starts after Chrome checks device capability, network conditions and available storage. Recent reporting on August 6 said Chrome now signals users need about 20GB of free disk space before the browser will fetch those models. Google’s own developer pages do not fix a single permanent model size, but they do confirm that the model size varies over time and that storage checks determine whether the download proceeds. ### Where does the 20GB figure come from? PiunikaWeb reported on August 6 that Google had updated a help page to say Chrome needs about 20GB of free disk space before downloading its on-device AI models. The report said Chrome also requires an “unmetered network connection,” which rules out many mobile hotspot connections for the initial fetch. Google’s developer documentation supports the broader mechanism. (piunikaweb.com) The Prompt API and “Get started with built-in AI” pages say Chrome checks whether the device can run the features, requires network access for the initial download, and notes that model size can change as the browser updates the model. Those pages also direct developers to `chrome://on-device-internals` to see the current size on a given machine. ### Is Chrome saying the model itself is 20GB? Google’s documentation says no fixed number should be treated as the permanent model size. The Prompt API page says “Gemini Nano’s exact size may vary as the browser updates the model,” and the model footprint can be checked in Chrome’s internal diagnostics page. Chrome’s built-in model management page says the browser chooses between different Gemini Nano variants after running device checks, including a GPU performance estimate. (developer.chrome.com) Google says Chrome may download a “larger, more capable” variant on some hardware, which helps explain why the free-space requirement can be higher than the compressed size users expect from a single model file. That is an inference from Google’s description of variant selection and storage gating, not a published breakdown of the 20GB figure. ### What happens after the model is downloaded? Google says the network requirement applies only to the initial download. The “Get started with built-in AI” page says subsequent use does not require a network connection and that no data is sent to Google or third parties when the model runs locally. Google also says Chrome can delete the model later if storage gets tight. The Prompt API and setup pages say that if available storage falls below 10GB after download, the model is removed from the device and will be downloaded again once the requirements are met. (developer.chrome.com) ### Which Chrome features depend on this local model? Google’s built-in AI pages say Gemini Nano in Chrome underpins APIs for prompting, writing, rewriting, summarizing and related features exposed to web apps and extensions. (developer.chrome.com) The company presents those APIs as local, browser-level capabilities rather than cloud calls. PiunikaWeb reported in June that Chrome users had already noticed a roughly 4GB on-device AI download tied to Gemini-related features, and that Google was testing more granular controls in Chrome Canary. (developer.chrome.com) That earlier reporting suggests Google has been adjusting how these local AI components are packaged and managed as the feature set expands. ### How can users or developers verify it on their own machines? (developer.chrome.com) Google tells developers to use `chrome://on-device-internals` to inspect the current built-in model state and size. Chromium source pages describe that interface as the debug UI for Chrome’s OnDeviceModelService. Google’s current developer guidance also says the initial download is triggered by the first call to a built-in AI API such as `Summarizer.create`. (piunikaweb.com) That means the next concrete check is not a future announcement but what Chrome reports locally on devices that meet the hardware, storage and network requirements. (developer.chrome.com 1) (developer.chrome.com 2)