# Grok 4.5 Goes Public as OpenAI Launches GPT-5.6 > Source: [https://icharles.com/articles/grok-45-public-launch-gpt-56](https://icharles.com/articles/grok-45-public-launch-gpt-56) (canonical) > Author: iCharles News — iCharles, https://icharles.com > Published: 2026-07-08 ## TL;DR xAI is releasing Grok 4.5 to the public on July 9, 2026. The model runs on a 1.5-trillion-parameter V9 foundation and includes supplemental training data from Cursor. Elon Musk described it as an Opus-class model that is faster and more token-efficient. The launch lands the same week OpenAI opens GPT-5.6 Sol, Terra, and Luna to the public — putting both companies' latest flagship models in head-to-head competition. ## What is Grok 4.5 and when does it go public? **Grok 4.5** is xAI's latest large language model, built on a 1.5-trillion-parameter V9 foundation with supplemental training data from Cursor, the AI coding assistant. Elon Musk announced on July 8, 2026 that SpaceXAI will release Grok 4.5 to the public the following day. Musk cited strong positive feedback from beta customers as the reason for the public rollout. The model entered private beta at SpaceX and Tesla on June 28. ## How does Grok 4.5 compare to Claude Opus? Musk described Grok 4.5 as an "Opus-class model" that runs faster, uses fewer tokens, and costs less. He said at the time of the private beta that it performs "close to, perhaps exceeding" Claude Opus. No system card or third-party benchmarks have been published to support those claims, according to [aiwire.news reporting on the private beta](https://aiwire.news/en/news/grok-45-private-beta). ## What is the architecture behind Grok 4.5? | Spec | Detail | |---|---| | Foundation model | V9 | | Parameter count | 1.5 trillion | | Comparison to prior model | ~3× larger than the 0.5T "v8-small" in production | | Supplemental training | Cursor IDE coding data | | Private beta start | June 28, 2026 | | Public release | July 9, 2026 | The Cursor training data signals xAI is targeting the AI coding market. That market is also contested by GitHub Copilot, Claude Code, and Cursor itself. Developers tracking [OpenAI inference cost cuts](/articles/openai-inference-cost-halved-optimization) will want to watch how Grok 4.5's token efficiency stacks up in practice. ## Why did xAI beta test at SpaceX and Tesla first? Using Musk's own companies as a proving ground let xAI run large-scale, real-workload testing without a public launch. That is a pattern other frontier labs do not have access to, according to [aiwire.news](https://aiwire.news/en/news/grok-45-private-beta). If Grok 4.5 cleared internal validation, a broader commercial release targeting enterprise developers could arrive quickly. The public launch on July 9 confirms it did. ## What is OpenAI releasing at the same time? OpenAI previewed its GPT-5.6 family in late June but limited access to a small group of vetted partners. On Wednesday, July 9, the company said GPT-5.6 Sol, Terra, and Luna will launch publicly on Thursday. "We're expanding preview access globally now," OpenAI posted, according to [BeInCrypto's coverage of the dual launch](https://beincrypto.com/grok-4-5-public-launch-openai/). Here's what we know so far: both companies are opening their latest flagship models to the public in the same week, which puts developers in a position to run direct comparisons immediately. ## What is the history between Musk and OpenAI? Musk co-founded OpenAI in 2015 and left the board in 2018. He sued OpenAI and Sam Altman in 2024, arguing they had broken an early pledge to run the AI venture as a nonprofit. A jury dismissed that lawsuit in May as untimely. The competing launches this week revive that rivalry in a more direct form. Builders following the [Claude paid users growth](/articles/claude-paid-users-growth-2026) story will recognize this as part of a broader battle for enterprise developer share. ## What does xAI's model roadmap look like? xAI has stated it intends to release entirely new models monthly through SpaceX for the rest of 2026. The Grok 4.5 public launch on July 9 is the next step in that schedule. Developers building on top of AI coding tools — already watching moves like [Meta banning Claude Code](/articles/meta-bans-claude-codex-distillation) over distillation concerns — now have another model to evaluate for coding workloads. --- **Key timeline:** - **June 28, 2026** — Grok 4.5 enters private beta at SpaceX and Tesla - **July 8, 2026** — Musk announces public release for the following day - **July 9, 2026** — Grok 4.5 public launch; OpenAI GPT-5.6 Sol, Terra, and Luna also launch publicly --- ## Frequently asked questions **When does Grok 4.5 go public?** Elon Musk announced on July 8, 2026 that SpaceXAI will release Grok 4.5 to the public on July 9, 2026. The decision followed a private beta that began on June 28 at SpaceX and Tesla. Musk said strong positive feedback from beta customers drove the decision to open access to the public. **How many parameters does Grok 4.5 have?** Grok 4.5 is built on xAI's V9 foundation model with 1.5 trillion parameters. That is approximately three times larger than the 0.5-trillion-parameter "v8-small" model currently in production. The model also includes supplemental training data from Cursor, an AI coding assistant, targeting the developer coding market. **Is Grok 4.5 better than Claude Opus?** Elon Musk claims Grok 4.5 performs "close to, perhaps exceeding" Claude Opus and describes it as an Opus-class model that is faster and more token-efficient. However, no system card or third-party benchmarks have been published to verify those claims as of the July 8 announcement. **What is GPT-5.6 and when does it launch?** GPT-5.6 is OpenAI's latest model family, which includes three variants: Sol, Terra, and Luna. OpenAI previewed the family in late June with limited access to vetted partners. The company announced on July 9 that all three variants would launch publicly on Thursday, the same day as Grok 4.5's public release. **Why did xAI use SpaceX and Tesla to test Grok 4.5?** xAI used SpaceX and Tesla as internal proving grounds to run large-scale, real-workload testing without a public launch. This approach let the company validate Grok 4.5 at scale before a broader commercial release. No other frontier AI lab has the same access to large internal enterprise deployments for pre-release testing.