LLM Reference

Claude Opus 4.8 vs Grok 4.3

Claude Opus 4.8 (2026) and Grok 4.3 (2026) are frontier-tier reasoning models from Anthropic and xAI. Claude Opus 4.8 ships a 1m-token context window, while Grok 4.3 ships a 1m-token context window. On pricing, Claude Opus 4.8 costs $5/1M input tokens; Grok 4.3 ranges from $1.25 to $2.50/1M input tokens by tier. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.

Claude Opus 4.8 is safer overall; choose Grok 4.3 when vision-heavy evaluation matters.

Decision scorecard

Local evidence first
SignalClaude Opus 4.8Grok 4.3
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitCoding, RAG, and AgentsRAG, Agents, and Long context
Context window1m1m
Cheapest output$25/1M tokens$2.50/1M tokens
Provider routes7 tracked4 tracked
Shared benchmarks0 rows0 rows

Decision tradeoffs

Choose Claude Opus 4.8 when...
  • Claude Opus 4.8 has broader tracked provider coverage for fallback and procurement flexibility.
  • Claude Opus 4.8 uniquely exposes Code execution, Computer use, and Parallel agents in local model data.
  • Local decision data tags Claude Opus 4.8 for Coding, RAG, and Agents.
Choose Grok 4.3 when...
  • Grok 4.3 has the lower cheapest tracked output price at $2.50/1M tokens.
  • Local decision data tags Grok 4.3 for RAG, Agents, and Long context.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output route or tier on this page.

Lower estimate Grok 4.3

Claude Opus 4.8

$10,250

Cheapest tracked route/tier: Anthropic

Grok 4.3

$1,625

Cheapest tracked route/tier: xAI Console

Estimated monthly gap: $8,625. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Claude Opus 4.8 -> Grok 4.3
  • Provider overlap exists on OpenRouter, Microsoft Foundry, and Vercel AI Gateway; start route-level A/B tests there.
  • Grok 4.3 is $22.50/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Code execution, Computer use, and Parallel agents before moving production traffic.
Grok 4.3 -> Claude Opus 4.8
  • Provider overlap exists on Microsoft Foundry, OpenRouter, and OpenRouter; start route-level A/B tests there.
  • Claude Opus 4.8 is $22.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Claude Opus 4.8 adds Code execution, Computer use, and Parallel agents in local capability data.

Specs

Specification
Released2026-05-282026-05-06
Context window1m1m
Parameters~0.5T
Architecturedecoder only-
LicenseProprietaryProprietary
Knowledge cutoff2026-012024-11

Pricing and availability

Pricing attributeClaude Opus 4.8Grok 4.3
Input price$5/1M tokens
0-200,001t
$1.25/1M tokens
200,001t+
$2.50/1M tokens
Output price$25/1M tokens
0-200,001t
$2.50/1M tokens
200,001t+
$5/1M tokens
Providers

Capabilities

CapabilityClaude Opus 4.8Grok 4.3
VisionYesYes
MultimodalYesYes
ReasoningYesYes
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionYesNo
IDE integrationNoNo
Computer useYesNo
Parallel agentsYesNo

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

The capability footprint differs most on code execution: Claude Opus 4.8. Both models share vision, multimodal input, reasoning mode, and function calling, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.

For cost, Claude Opus 4.8 lists $5/1M input and $25/1M output tokens on the cheapest tracked provider, while Grok 4.3 lists tiered pricing: 0-200,001t is $1.25/1M input and $2.50/1M output; 200,001t+ is $2.50/1M input and $5/1M output. A 70/30 input-output blend puts Grok 4.3 lower by about $9.38 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 7 providers versus 4, so concentration risk also matters.

Choose Claude Opus 4.8 when coding workflow support and broader provider choice are central to the workload. Choose Grok 4.3 when vision-heavy evaluation and lower cheapest-tier input-token cost are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.

FAQ

Which has a larger context window, Claude Opus 4.8 or Grok 4.3?

Claude Opus 4.8 supports 1m tokens, while Grok 4.3 supports 1m tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.

Which is cheaper, Claude Opus 4.8 or Grok 4.3?

Claude Opus 4.8 lists $5/1M input and $25/1M output tokens on the cheapest tracked provider. Grok 4.3 lists tiered pricing: 0-200,001t is $1.25/1M input and $2.50/1M output; 200,001t+ is $2.50/1M input and $5/1M output. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. Provider discounts or batch pricing can still change the final bill.

Is Claude Opus 4.8 or Grok 4.3 open source?

Claude Opus 4.8 is listed under Proprietary. Grok 4.3 is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.

Which is better for vision, Claude Opus 4.8 or Grok 4.3?

Both Claude Opus 4.8 and Grok 4.3 expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Which is better for multimodal input, Claude Opus 4.8 or Grok 4.3?

Both Claude Opus 4.8 and Grok 4.3 expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.

Where can I run Claude Opus 4.8 and Grok 4.3?

Claude Opus 4.8 is available on Anthropic, AWS Bedrock, GCP Vertex AI, Microsoft Foundry, and OpenRouter. Grok 4.3 is available on xAI Console, OpenRouter, Microsoft Foundry, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-28. Data sourced from public model cards and provider documentation.