Grok 4.5 Beta Testing Begins at SpaceX and Tesla
The shift to a 1.5 trillion parameter base model and the integration of Cursor data mark a notable step in xAI's model development, with internal testing at SpaceX and Tesla providing early validation.
Reporting from 1 sources: GIGAZINE.
Elon Musk announced Grok 4.5, based on a 1.5 trillion parameter model called V9, with additional training on Cursor data. Beta testing is underway at SpaceX and Tesla. Initial evaluations show performance close to or exceeding Claude Opus in some cases. Musk said new models trained from scratch will release monthly from SpaceX.
Elon Musk posted an overview of Grok 4.5 on X on June 28, 2026 Japan time. The model is built on the V9 base, which has 1.5 trillion parameters, and was further trained using data from Cursor, the AI agent tool developed by Anysphere. SpaceX announced an agreement to acquire Anysphere on June 16, 2026. Beta testing of Grok 4.5 is being conducted internally at SpaceX and Tesla. Musk stated that initial evaluations indicate performance close to Claude Opus, and in some cases exceeding it, though the specific version of Claude Opus used for comparison was not specified. Improvements continue through reinforcement learning, and the Grok Build harness is also being updated. Musk said new models trained from scratch will be released from SpaceX every month this year.
Synthesized by Yomimono from the 1 cited source below, including Japanese-language reporting where cited, then editorially reviewed before publishing.