Claude Fable 5 vs Grok 4.5

Claude Fable 5 is Anthropic's most capable public model, generally available worldwide and priced at $10 input and $50 output per million tokens. xAI released Grok 4.5 on July 8, 2026 for coding, agentic tasks, and knowledge work, but had not published per-token pricing as of this writing.

Fable 5 is Anthropic's top tier for software engineering, knowledge work, vision, and research. Grok 4.5 leans on broad platform integrations, including Databricks and Amazon Bedrock, for agentic task management.

This page compares availability, price, capability, and compliance so you can pick the right model for your workload.

Claude Fable 5 vs. Grok 4.5: Side-by-Side

Price: Fable 5 costs more, positioned as the top tier

Claude Fable 5 is Anthropic's premium tier, priced at $10 per million input tokens and $50 per million output tokens (Anthropic) — the highest price point in Anthropic's current lineup.

xAI has not published official per-token pricing for Grok 4.5 as of this writing. Its predecessor, Grok 4.3, was priced far lower, at $1.25 input and $2.50 output per million tokens. If Grok 4.5 lands near that range, it would substantially undercut Fable 5 on cost — confirm current pricing directly with xAI.

• Claude Fable 5: $10 input / $50 output per million tokens.
• Grok 4.5: pricing not yet published.
• Grok 4.3 (prior flagship): $1.25 / $2.50 per million tokens.

→ Compare per-token pricing for every AI model

Capability and best-fit work

Claude Fable 5 is Anthropic's most capable public model for software engineering, knowledge work, vision, and scientific research.

Grok 4.5 targets coding, agentic tasks, and knowledge work, with broad platform integrations including Databricks and Amazon Bedrock. For teams already standardized on those platforms, that integration depth is a practical advantage.

• Fable 5: top-tier capability across software engineering, knowledge work, vision, research.
• Grok 4.5: agentic tasks with Databricks/Bedrock integrations.

Claude Fable 5 vs Grok 4.5 benchmarks: what's actually published

Neither Claude Fable 5's nor Grok 4.5's maker has published a same-day, apples-to-apples benchmark suite pitting these two exact versions against each other, so treat any comparison here as directional rather than a verified head-to-head.

Vendors have not published a directly comparable, head-to-head SWE-bench Verified score for these exact current-generation versions as of this writing. The most recent published reference points are Claude Opus 4.8 at about 88.6%, GPT-5 at about 74%, Grok 4 at about 75%, and Gemini 2.5 Pro at about 71% (Google) — treat these as directional, not a same-generation apples-to-apples test.

Until both vendors publish a matched benchmark run, the more reliable signal is a short pilot on your own tasks — coding, drafting, or analysis representative of your real workload.

• Claude Opus 4.8: ~88.6% on SWE-bench Verified.
• GPT-5: ~74% on SWE-bench Verified.
• Grok 4: ~75% on SWE-bench Verified.
• Gemini 2.5 Pro: ~71% on SWE-bench Verified.

Compliance: Fable 5's coverage is the most documented

Claude Fable 5 ships with SOC 2, ISO 27001, ISO 42001, and a HIPAA BAA, plus a mandatory 30-day safety-retention policy.

Grok 4.5's certification status was not detailed in public materials reviewed for this comparison. Confirm SOC 2 status, HIPAA BAA availability, and data-retention terms directly with xAI before sending regulated data.

• Fable 5: SOC 2, ISO 27001, ISO 42001, HIPAA BAA, 30-day safety retention.
• Grok 4.5: confirm current certifications directly with xAI.

How to choose for your business

Choose Claude Fable 5 if you need the most capable, most thoroughly documented option for the hardest knowledge work today. Choose Grok 4.5 if your stack runs on Databricks or Amazon Bedrock and you want to evaluate a newer, likely lower-cost model.

Run a short pilot before committing budget to Grok 4.5, given its pricing and certifications were not fully public at the time of writing.

• Top-tier capability and documented compliance: Claude Fable 5.
• Databricks/Bedrock-native stack, evaluating a new model: Grok 4.5.

The Verdict

Claude Fable 5 is Anthropic's most capable and most thoroughly documented model, but it's also the most expensive of the two — $10/$50 per million tokens against Grok 4.5's unpublished pricing.

If your business already runs on Databricks or Amazon Bedrock and can tolerate evaluating a newer release, pilot Grok 4.5 directly. For the hardest knowledge work with documented compliance, Fable 5 remains the safer choice today.