Quick verdict

Grok or Claude Fable 5.1?

Choose Grok when coding, agent workflows, real-time web/x context and productivity integrations is the closer match. Choose Claude Fable 5.1 when ambitious coding, research and long-running asynchronous projects matters more. Test both on the same real tasks before moving a production workflow.

Choose Grok for

Coding, agent workflows, real-time web/X context and productivity integrations

Choose Claude Fable 5.1 for

Ambitious coding, research and long-running asynchronous projects

SpaceXAI · Product

Grok

Coding, agent workflows, real-time web/X context and productivity integrations

Official specification ↗
Anthropic · Model

Claude Fable 5.1

Anthropic's frontier model for demanding reasoning and long-horizon agentic work.

Official specification ↗
01

Side-by-side comparison

CategoryGrokClaude Fable 5.1
ProviderSpaceXAIAnthropic
TypeProduct · General AssistantModel · Frontier reasoning model
Pricing summaryFree and paid access varies by product/plan; API pricing is model-specific$10 input, $0.25 cache read and $50 output per 1M tokens
Input priceProduct or plan pricing$10 / 1M tokens
Cached inputNot directly comparable$0.25 / 1M tokens
Output priceProduct or plan pricing$50 / 1M tokens
Context windowVaries by included model and plan1M tokens
Maximum outputVaries by included model and surface128K tokens
Knowledge cutoffModel-dependent; web access may add current informationJune 2026
ReasoningVaries by selected model or modeAdaptive, always on; high default effort
Relative speedVaries by model, plan and workloadSlower
Input modalitiesSee documented product featuresText and image
Output modalitiesSee documented product featuresText
Tools and integrationsGrok 4.6 for long-running agent tasks; Real-time web and X research tools; Grok Build and Agent Tools API; Grok Imagine image and video creationClaude API tool use, computer use and agent workflows
API / accessProduct surface; see official source for API availabilityClaude Messages API
Best fitCoding, agent workflows, real-time web/X context and productivity integrationsAmbitious coding, research and long-running asynchronous projects
CompanySpaceXAIAnthropic
Product categoryProduct · General AssistantModel · Frontier reasoning model
Current pricing noteFree and paid access varies by product/plan; API pricing is model-specific$10 input, $0.25 cache read and $50 output per 1M tokens
Best suited toCoding, agent workflows, real-time web/X context and productivity integrationsAmbitious coding, research and long-running asynchronous projects
Key capabilitiesGrok 4.6 for long-running agent tasks; Real-time web and X research tools; Grok Build and Agent Tools API; Grok Imagine image and video creationLong-horizon agents; Repository-scale coding; Multistep research; Vision and document work
Last verified2026-08-242026-09-08
Official product sourcehttps://x.ai/news/grok-4-6https://platform.claude.com/docs/en/models/fable-5-1/overview
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How we reached this verdict

We looked at the things that affect everyday use: what each product can do, how its plans are structured, where it fits into your existing workflow, and what the provider currently documents. Benchmark results are useful context, but they are not a universal winner score because test settings and tools vary.

03

Common questions

Grok or Claude Fable 5.1: which should I choose?

Choose Grok for coding, agent workflows, real-time web/x context and productivity integrations. Choose Claude Fable 5.1 for ambitious coding, research and long-running asynchronous projects. Validate the decision with your own prompts and total task cost.

Is Grok cheaper than Claude Fable 5.1?

Pricing units can differ. Grok: Free and paid access varies by product/plan; API pricing is model-specific. Claude Fable 5.1: $10 input, $0.25 cache read and $50 output per 1M tokens. Check tool charges, plan limits, caching and long-context rules before comparing totals.

Which is better for coding and agent work?

Capability depends on the selected product surface, tools and harness. Grok is positioned for coding, agent workflows, real-time web/x context and productivity integrations; Claude Fable 5.1 is positioned for ambitious coding, research and long-running asynchronous projects. Run the same repository task on both.

How do their context windows compare?

Grok lists Varies by included model and plan; Claude Fable 5.1 lists 1M tokens. A larger limit does not by itself guarantee better retrieval or lower cost.

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Official sources

Use these provider pages to confirm current features, pricing and availability.

AI tools change quickly. We checked this page on 2026-09-08. Before you subscribe, confirm the latest price, regional availability and usage limits on the provider website.