Grok 4.5 vs Claude Fable 5 (2026): Price, Benchmarks and EU Availability
Grok 4.5 costs 5x less on input than Claude Fable 5, but loses 4 of 5 benchmarks on xAI's own chart. Verified prices, evals and the EU availability gap.
Grok 4.5 is not a cheaper Claude Fable 5. It is a different bet. If you want the highest measured resolve rate on hard, well-specified engineering tasks, Fable 5 still wins on xAI's own chart by nearly 16 points on SWE Bench Pro, and it carries twice the context window. If you are running fleets of unattended agents where the job is long, the specification is loose and cost compounds across thousands of rollouts, Grok 4.5 is the better instrument: it leads SWE Marathon at 29.0% pass@1, it costs 5x to 8x less per token, and xAI reports it resolves a SWE Bench Pro task with 4.2x fewer output tokens than Opus 4.8, which widens the effective gap well beyond the sticker price. Two practical constraints decide most real cases before capability does. First, Grok 4.5 was not available in the EU at launch, with availability expected mid-July 2026, so European teams shipping this week do not have a choice to make. Second, Claude Fable 5 stops being included on paid plans on July 12, 2026, after which every token bills at roughly $10 and $50 per million. If you are an EU team with a hard deadline, use Fable 5 and turn on prompt caching, batching and spend caps before the 12th. If you are cost-bound, agent-heavy and outside the EU, Grok 4.5 is the most capable model per dollar and per second currently available.
Detailed Comparison
A side-by-side analysis of key factors to help you make the right choice.
| Factor | Grok 4.5Recommended | Claude Fable 5 | Winner |
|---|---|---|---|
| Price per million tokens | $2 input, $6 output at xAI's published list price | $10 input, $50 output, which is 5x more on input and 8.3x more on output | |
| Peak coding capability on hard tasks | 64.7% resolve rate on SWE Bench Pro and 62.0% on DeepSWE 1.0: strong, but not frontier-leading | 80.4% on SWE Bench Pro and 66.1% on DeepSWE 1.0, the highest scores on xAI's own launch chart | |
| Long-horizon agentic resolution | 29.0% pass@1 on SWE Marathon, the best result of any model xAI charted, including Opus 4.8 at 26.0% | 24.0% pass@1 on SWE Marathon, behind both Grok 4.5 and Opus 4.8 | |
| Token efficiency and effective cost | Resolves an average SWE Bench Pro task with 15,954 output tokens, about 4.2x fewer than Opus 4.8 (max) | Emits substantially more output tokens per task, so real spend runs above the headline rate | |
| Context window | 500,000 tokens | 1,000,000 tokens, twice Grok 4.5's window | |
| Availability in the European Union (as of July 10, 2026) | Not available in the EU in any SpaceXAI product or the API console; xAI expects EU availability in mid-July 2026 | Available to European customers today through Anthropic's standard channels | |
| Terminal and tool use | 83.3% on Terminal Bench 2.1 | 84.3% on Terminal Bench 2.1, a one-point gap that sits inside benchmark noise | |
| Billing predictability | A flat published per-token rate, plus free usage in Grok Build and Cursor for a limited period after launch | Included on paid plans only through July 12, 2026, after which every token bills at the premium rate | |
| Total Score | 4/ 8 | 3/ 8 | 1 ties |
Key Statistics
Real data from verified industry sources to support your decision.
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Anthropic (@claudeai)
All statistics come from verified third-party sources. Source, year, and direct link are shown on each metric.
When to Choose Each Option
Clear guidance based on your specific situation and needs.
Choose Grok 4.5 when...
- You run unattended, long-horizon coding agents, where SWE Marathon-style resolution matters more than single-shot benchmark peaks.
- Token spend is your binding constraint: 5x to 8x cheaper tokens combined with 4.2x fewer output tokens compounds fast across a fleet of agents.
- You already build in Cursor, which trained alongside Grok 4.5 and ships it on every plan.
- You operate outside the European Union, or you can wait for xAI's mid-July 2026 EU rollout.
Choose Claude Fable 5 when...
- You need the highest measured resolve rate on hard, well-specified engineering work, where Fable 5 leads SWE Bench Pro by nearly 16 points.
- Your prompts routinely pass 500,000 tokens and you need the full one-million-token context window.
- You are an EU company that has to ship this week and cannot wait for regional availability.
- Frontier capability justifies the premium, and you have prompt caching, batching and spend caps in place before July 12, 2026.
Our Recommendation
Grok 4.5 is not a cheaper Claude Fable 5. It is a different bet. If you want the highest measured resolve rate on hard, well-specified engineering tasks, Fable 5 still wins on xAI's own chart by nearly 16 points on SWE Bench Pro, and it carries twice the context window. If you are running fleets of unattended agents where the job is long, the specification is loose and cost compounds across thousands of rollouts, Grok 4.5 is the better instrument: it leads SWE Marathon at 29.0% pass@1, it costs 5x to 8x less per token, and xAI reports it resolves a SWE Bench Pro task with 4.2x fewer output tokens than Opus 4.8, which widens the effective gap well beyond the sticker price. Two practical constraints decide most real cases before capability does. First, Grok 4.5 was not available in the EU at launch, with availability expected mid-July 2026, so European teams shipping this week do not have a choice to make. Second, Claude Fable 5 stops being included on paid plans on July 12, 2026, after which every token bills at roughly $10 and $50 per million. If you are an EU team with a hard deadline, use Fable 5 and turn on prompt caching, batching and spend caps before the 12th. If you are cost-bound, agent-heavy and outside the EU, Grok 4.5 is the most capable model per dollar and per second currently available.
Frequently Asked Questions
Common questions about this comparison answered.
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