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Grok models

Grok models, from Grok-1 to Grok 4.7: every release in one place

Release dates, context windows and status for each Grok model, plus which ones SpaceXSI has retired from its API.

Checked October 18, 2026By GrokMag editorsIndependent · not affiliated with SpaceXSI, xAI or X
Short answer

The newest Grok model is Grok 4.7, released September 21, 2026 with a 500k-token context window at $2/$6 per million tokens. Grok 4.6, 4.5, 4.3, the 4.20 family and grok-build-0.1 are also current. Grok 3, Grok 4, Grok 4 Fast, Grok 4.1 Fast and Grok Code Fast 1 were retired from the API on May 15, 2026.

Every Grok model so far

SpaceXSI (formerly xAI) has shipped a new Grok model every few months since late 2023. The pace sped up in 2026, with five major releases between February and September. The table lists each model, when it arrived, its context window where the company published one, and what made it notable.

ModelReleasedContextNotes
Grok-1Nov 3, 2023 (preview)Not stated314B-parameter mixture-of-experts model. Weights released Mar 17, 2024 under Apache 2.0.
Grok-1.5Announced Mar 28-29, 2024128kReached Premium users May 15, 2024. Grok-1.5V (vision) was previewed but never released.
Grok-2 and Grok-2 miniBeta Aug 13-14, 2024; shipped Aug 20, 2024Not statedAurora image generation followed on Dec 9, 2024. Grok 2.5 weights were published in Aug 2025.
Grok 3 and Grok 3 miniFeb 17, 2025Not statedIntroduced Think mode. On the API from Apr 3, 2025. Retired May 15, 2026.
Grok 4 and Grok 4 HeavyJul 9, 2025256kAPI price $3/$15. Heavy is the multi-agent version. grok-4-0709 retired May 15, 2026.
Grok Code Fast 1Aug 28, 2025Not statedCheap coding model at $0.20/$1.50. Retired May 15, 2026.
Grok 4 FastSep 19, 20252MRetired May 15, 2026 and routed to grok-4.3.
Grok 4.1Nov 17, 20254.1 Fast: 2MGrok 4.1 Fast came to the API Nov 19, 2025. The fast model is now retired.
Grok 4.20Beta Feb 17, 2026; API Mar 10, 20261MBuilt on a 4-agent system. Reasoning, non-reasoning and multi-agent versions.
Grok 4.3Late Apr / May 1, 20261M$1.25/$2.50. Can create spreadsheets, PDFs and slide decks.
grok-build-0.1Early access May 19, 2026256kCoding model behind Grok Build. $1/$2.
Grok 4.5Jul 8, 2026 (release notes)500kTrained alongside Cursor. $2/$6.
Grok 4.6Aug 12, 2026500k$2/$6. Four effort levels.
Grok 4.7Sep 21, 2026500kCurrent flagship. $2/$6.

Prices are USD per million input and output tokens on the API. “Not stated” means our sources do not give a figure.

Dates that differ: Grok 4.5 appears as July 8, 2026 in the release notes, but the announcement post on x.ai is dated July 16. Grok 4.3 is listed as April 2026 by Wikipedia and as the night of April 30 to May 1 by VentureBeat.

Which Grok models are current

As of October 18, 2026, the SpaceXSI pricing page lists these text models. The newest is Grok 4.7, which also powers the Grok Build coding agent.

API modelContextInput / cached / output (per 1M tokens)
grok-4.7500k$2.00 / $0.50 / $6.00
grok-4.6500k$2.00 / $0.50 / $6.00
grok-4.5500k$2.00 / $0.30 / $6.00
grok-4.31M$1.25 / $0.20 / $2.50
grok-4.20-0309 (reasoning, non-reasoning, multi-agent)1M$1.25 / $0.20 / $2.50
grok-build-0.1256k$1.00 / $0.20 / $2.00

Prompts over 200k tokens switch to long-context rates, which are double the standard rates and apply to the whole request. A faster version, Grok 4.7 Fast, exists but is only offered inside Cursor and Grok Build, not on the public API. If you are unsure what a context window is, it is the amount of text a model can consider at once.

Models retired on May 15, 2026

SpaceXSI retired a batch of older models from its API at 12:00 PM PT on May 15, 2026. Do not build on these names:

  • grok-3: the February 2025 model.
  • grok-4-0709: the original Grok 4.
  • grok-4-fast: now routed to grok-4.3.
  • grok-4.1-fast: the November 2025 fast model.
  • grok-code-fast-1: now routed to grok-build-0.1.
Billing is unclear: the retirement guide says calls to old names are billed at grok-4.3 rates ($1.25/$2.50), while the pricing page lists grok-build-0.1 at $1/$2. It is not clear which rate a redirected grok-code-fast-1 call pays. Check your console invoices.

Standard, Fast and Heavy versions

Grok models often come in more than one version. Fast versions trade price for speed: Grok 4.7 Fast runs on faster infrastructure at twice the token price. Heavy versions run several agents on one problem and combine their answers. That approach started with Grok 4 Heavy in July 2025 and continued with the multi-agent Grok 4.20. Our Grok Heavy guide covers how it works and why plan access is unclear after the October 12, 2026 pricing change.

Recent models also offer effort levels. Grok 4.7 accepts low, medium, high (the default) and xhigh. Higher effort usually means better answers, more tokens and a bigger bill.

Open-weight Grok models

Only two Grok models have public weights: Grok-1, released under Apache 2.0 in March 2024, and Grok 2.5, released in August 2025 under a custom license. Musk promised to open Grok 3 within about six months of August 2025, and that did not happen. On May 25, 2026, he said a “0.5T model” would be open-sourced toward the end of 2026. Details are in our open-source Grok guide.

What comes after Grok 4.7

Grok 4.8 has not been released as of October 18, 2026. On September 14, 2026, Musk said it would finish training that week, that it has about 2.5T parameters and that it uses a new C++ training stack. These are his statements, not official specs. Musk’s stated order is 4.7, then 4.8, then 4.9, then Grok 5, and Grok 5 has no release date. We track every claim on our Grok 5 tracker.

Questions people ask

What is the latest Grok model?

Grok 4.7, released September 21, 2026. It has a 500k-token context window and costs $2 per million input tokens and $6 per million output tokens on the API. See our Grok 4.7 guide.

Is Grok 3 still available?

Not on the API. grok-3 was retired on May 15, 2026, along with grok-4-0709, grok-4-fast, grok-4.1-fast and grok-code-fast-1.

Which Grok model has the largest context window?

Among current API models, grok-4.3 and the grok-4.20 models offer 1M tokens. Grok 4 Fast and Grok 4.1 Fast offered 2M, but both are retired.

When is Grok 5 coming out?

There is no date. Earlier targets passed, and Musk says Grok 4.8 and 4.9 come first. Follow our Grok 5 tracker.

Current flagshipGrok 4.7: specs, price and real benchmark resultsRead it →Multi-agentGrok Heavy explainedRead it →Coming nextGrok 5 trackerRead it →
Sources (checked October 18, 2026)
  1. SpaceXSI API pricing (fetched Oct 18, 2026)
  2. SpaceXSI May 15 model retirement guide (fetched Oct 18, 2026)
  3. SpaceXSI release notes (fetched Oct 18, 2026)
  4. SpaceXSI: Grok 4.7 announcement (Sep 2026)
  5. SpaceXSI docs: Grok 4.7 (fetched Oct 18, 2026)
  6. SpaceXSI: Grok 4.5 announcement (Jul 2026)
  7. xAI: Grok Code Fast 1 (Aug 2025)
  8. xAI: Grok 4.1 (Nov 2025)
  9. Wikipedia: Grok (chatbot) (fetched Oct 18, 2026)
  10. VentureBeat on Grok 4.3 (May 1, 2026)
  11. Keywords AI on Grok 4 (Jul 16, 2025)
  12. OpenRouter: Grok 4 Fast (fetched Oct 18, 2026)
  13. Verdent guide to Grok 4.20 (fetched Oct 18, 2026)
  14. Open-source 0.5T model tracker (fetched Oct 18, 2026)
  15. GeoToolbox on Grok 4.8 and Grok 5 (Sep 2026)