Source: Epoch AI (CC BY 4.0). ECI is Epoch's item-response model over many benchmarks; each model page shows its 90% confidence interval.
Only models with both an ECI score and an OpenRouter price. Normalisation: 75% input + 25% output price. Click a point to open the model.
| # | Model | ECI ↑ | Context | In $/M | Weights | Released |
|---|---|---|---|---|---|---|
| 1 | Grok-2 (Dec 2024) | 130.5 | — | — | Closed | 12 Dec 2024 |
| 2 | Grok 3 | 138.3 | — | — | Closed | 9 Apr 2025 |
| 3 | Grok-3 mini | 140.3 | — | — | Closed | 24 Jun 2025 |
| 4 | Grok 4 Fast | 144.2 | — | — | Closed | 19 Sep 2025 |
| 5 | Grok 4 | 146.5 | — | — | Closed | 9 Jul 2025 |
| 6 | Grok 4.3 Beta | 149.1 | — | — | Closed | 17 Apr 2026 |
| 7 | Grok 4.20 xAI· reasoning | 152.0 | 2M | $1.25 | Closed | 17 Feb 2026 |
| 8 | Grok 4.5 xAI· reasoning | 154.0 | 500K | $2.00 | Closed | 8 Jul 2026 |
| 9 | Grok 4.6 xAI· reasoning | 156.5 | 500K | $2.00 | Closed | 12 Aug 2026 |
| 10 | Grok 4.7 xAI· reasoning | — | 500K | $1.60 | ? | 21 Sep 2026 |
| 11 | Grok 4.3 xAI· reasoning | — | 1M | $1.25 | ? | 30 Apr 2026 |
| 12 | Grok 4.3 (batch) xAI· reasoning | — | 1M | $1.00 | ? | 30 Apr 2026 |
| 13 | Grok 4.7 (unknown) | — | — | — | Closed | 21 Sep 2026 |
| 14 | Grok 4.7 (xhigh) | — | — | — | Closed | 21 Sep 2026 |
| 15 | Grok 4.6 (xhigh) | — | — | — | Closed | 12 Aug 2026 |
| 16 | Grok 4.6 (medium) | — | — | — | Closed | 12 Aug 2026 |
| 17 | Grok 4.6 (low) | — | — | — | Closed | 12 Aug 2026 |
| 18 | Grok 4.6 (unknown) | — | — | — | Closed | 12 Aug 2026 |
| 19 | Grok 4.5 (medium) | — | — | — | Closed | 8 Jul 2026 |
| 20 | Grok 4.5 (low) | — | — | — | Closed | 8 Jul 2026 |
| 21 | Grok 4.5 (unknown thinking) | — | — | — | Closed | 8 Jul 2026 |
| 22 | Grok Build 0.1 xAI· reasoning | — | 256K | $1.00 | ? | 20 May 2026 |
| 23 | Grok 4.20 Multi-Agent xAI· reasoning | — | 2M | $1.25 | ? | 31 Mar 2026 |
| 24 | Grok 4.1 Fast | — | — | — | Closed | 19 Nov 2025 |
| 25 | Grok 4.1 | — | — | — | Closed | 17 Nov 2025 |
| 26 | grok-code-fast-1 | — | — | — | ? | 28 Aug 2025 |
| 27 | Grok 4 Heavy (web app) | — | — | — | Closed | 10 Jul 2025 |