Claude Fable 5.1 vs Grok 4.5
Each agent graded on the same private suites, running headless through its own tools. Advantages are oriented so a win is a win, whichever way the metric runs.
| Dimension | Claude Fable 5.1 | Grok 4.5 | Advantage |
|---|---|---|---|
| Capability | 73% | 60% | +13% (Claude Fable 5.1 leads) |
| Median task time | 1m 46s | 3m 9s | 1m 24s faster (Claude Fable 5.1 leads) |
| Approx. task cost | $0.026 / task | $0.032 / task | $0.006 / task lower (Claude Fable 5.1 leads) |
Claude Fable 5.1: 28.0% of Claude Max 20x (28.0% / 5h, 5.0% / 1w) per run. Its weekly limit holds about 7.2 of the week's 33.6 5h windows. Grok 4.5: 6.9% of SuperGrok (6.9% / 1w) per run. Each figure is a share of that agent's own plan, so there is no delta to draw.
Only Claude Fable 5.1 has run this suite, so there is no head-to-head yet.
| Dimension | Claude Fable 5.1 | Grok 4.5 | Advantage |
|---|---|---|---|
| Capability | 85% | 59% | +26% (Claude Fable 5.1 leads) |
| Median task time | 3m 48s | 3m 40s | 8s faster (Grok 4.5 leads) |
| Approx. task cost | $0.025 / task | $0.031 / task | $0.006 / task lower (Claude Fable 5.1 leads) |
Claude Fable 5.1: 1.8% of Claude Max 20x (1.8% / 5h, 0.2% / 1w) per good solve. Its weekly limit holds about 7.2 of the week's 33.6 5h windows. Grok 4.5: 0.4% of SuperGrok (0.4% / 1w) per good solve. Each figure is a share of that agent's own plan, so there is no delta to draw.
Grades and deltas are comparable only within a suite version. See methodology.
Frequently asked questions
Which is better for coding, Claude Fable 5.1 or Grok 4.5?
Both clear tier 4 of 5, but Claude Fable 5.1 scores higher on capability: 73% versus 60% on real-world@v3, our private suite of real-world coding problems. Latest measurement 2026-09-01.
How much do Claude Fable 5.1 and Grok 4.5 cost?
Claude Fable 5.1 runs on Claude Max 20x at $200/month (public price as of 2026-08-05). Grok 4.5 runs on SuperGrok at $30/month (public price as of 2026-07-20).