How much does Grok 4 Fast cost?

We do not hold a list price for Grok 4 Fast yet, so we cannot compare its cost. Check the maker's own price page.

Is Grok 4 Fast open source?

We list Grok 4 Fast as closed: it is used through its maker's apps or API and its weights are not published (Epoch AI lists its access as "API access").

How good is Grok 4 Fast compared with other AI models?

On the Epoch Capabilities Index, Grok 4 Fast scores 144.1 (likely range 141.6 to 146.3), which ranks 94 of 270 models we track. On Arena's human-vote text board it is ranked 90 of 166. Scores close together are a tie in practice.

How does Grok 4 Fast compare with Claude Opus 4.1?

Claude Opus 4.1 scores higher on 3 of 4 shared quality measures, Grok 4 Fast on 0. 1 measure is too close to call. See the full comparison for every measure.

How current are these numbers for Grok 4 Fast?

The newest data on this page is dated 26 Oct 2026. Scores come from Epoch AI and Arena, prices from the open LiteLLM price list.

AI Rankings

Grok 4 Fast: Score, Price and Context Window

Where Grok 4 Fast from xAI ranks, what it costs and how much text it can read, in plain numbers with the sources.

Data updated 26 Oct 2026

xAI
Closed weights
Released Sep 2025

Its score range overlaps with Gemini 3.1 Flash-Lite, the model just above it, so a small gap in rank is not a meaningful difference.

Key facts

Overall score: 144.1; Rank 94 of 270. Likely range 141.6 to 146.3.
Human preference: chat: 1419; Rank 90 of 166. 6,337 votes, at the "Non-Reasoning" setting.
Human preference: coding: 1457; Rank 96 of 166. 1,183 votes, at the "Non-Reasoning" setting.
Human preference: web pages: 1160; Rank 85 of 85. 743 votes, at the "Reasoning" setting.
Weights: Closed; Used through the maker's apps or API (Epoch AI: API access).

We do not have a list price and a context window size for Grok 4 Fast yet. It is shown as "Not measured" rather than guessed.

Try itGrok in our AI tools directoryConversational AI assistant for writing, coding, visual creation, and live information from the web and X.

How Grok 4 Fast stacks up

Each strip shows every model we track as faint bars. The dot is this model. Better is always to the right, even for price.

Grok 4 Fast compared with all models we trackOverall capability: 144.1. Better than 65% of the other 269 models. Human preference: chat: 1419. Better than 46% of the other 165 models. Human preference: coding: 1457. Better than 42% of the other 165 models. Human preference: web pages: 1160. Better than 0% of the other 84 models.

Overall capability144.1
Better than 65% of the other 269 modelsUpper half
Epoch Capabilities Index: one score that combines many tests.
Human preference: chat1419
Better than 46% of the other 165 models
How often people pick its answers over another model's on Arena.
Human preference: coding1457
Better than 42% of the other 165 models
How often people pick its answers to coding questions on Arena.
Human preference: web pages1160
Better than 0% of the other 84 models
How often people pick the web pages and small apps it builds on Arena.

Compared with the other published models that have each measure. Data updated 26 Oct 2026.

Where Grok 4 Fast ranks

Leaderboards it appears on, best placing first.

See all leaderboards

Test results

Each test checks one kind of skill. Place shows where it stands among the models that took that test.

ARC-AGI-2
Visual puzzles where the AI must work out a new rule from a few examples and apply it. They test picking up a new idea quickly, not recalling facts.
5.3%
Place 58 of 86

Similar models

Models from other makers with a similar overall score.

Learn more

Questions about Grok 4 Fast

How much does Grok 4 Fast cost?: We do not hold a list price for Grok 4 Fast yet, so we cannot compare its cost. Check the maker's own price page.
Is Grok 4 Fast open source?: We list Grok 4 Fast as closed: it is used through its maker's apps or API and its weights are not published (Epoch AI lists its access as "API access").
How good is Grok 4 Fast compared with other AI models?: On the Epoch Capabilities Index, Grok 4 Fast scores 144.1 (likely range 141.6 to 146.3), which ranks 94 of 270 models we track. On Arena's human-vote text board it is ranked 90 of 166. Scores close together are a tie in practice.
How does Grok 4 Fast compare with Claude Opus 4.1?: Claude Opus 4.1 scores higher on 3 of 4 shared quality measures, Grok 4 Fast on 0. 1 measure is too close to call. See the full comparison for every measure.
How current are these numbers for Grok 4 Fast?: The newest data on this page is dated 26 Oct 2026. Scores come from Epoch AI and Arena, prices from the open LiteLLM price list.

Where this data comes from

Epoch AI: Benchmark data: Epoch AI, 'Capabilities & benchmarking', epoch.ai/benchmarks (CC BY 4.0). We match models across sources, rank them and show them in charts. Scores are not changed. Epoch AI does not endorse this site.
Arena (formerly LMArena): Human-preference ratings: Arena (arena.ai) leaderboard dataset, CC BY 4.0. We keep the latest published ratings, match them to models from other sources and rank them. Ratings are not changed. Arena does not endorse this site.

Newest data on this page: 26 Oct 2026. Prices are list prices and change often, so confirm on the maker's site before you buy. Sponsors never change a score or an order. How we calculate this · Report a mistake