LLM Reference

GPT-5 vs Grok 4

GPT-5 (2025) and Grok 4 (2025) are frontier-tier reasoning models from OpenAI and xAI. GPT-5 ships a 400k-token context window, while Grok 4 ships a 256k-token context window. On SWE-bench Verified, Grok 4 leads by 1.8 pts. On pricing, both list $1.25/1M input tokens on the cheapest tracked route. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.

GPT-5 is safer overall; choose Grok 4 when coding workflow support matters.

Decision scorecard

Local evidence first
SignalGPT-5Grok 4
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window400k256k
Cheapest output$10/1M tokens$2.50/1M tokens
Provider routes4 tracked4 tracked
Shared benchmarks2 rowsSWE-bench Verified leader

Decision tradeoffs

Choose GPT-5 when...
  • GPT-5 leads the largest shared benchmark signal on Aider Polyglot by 8.4 points.
  • GPT-5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Local decision data tags GPT-5 for Coding, RAG, and Agents.
Choose Grok 4 when...
  • Grok 4 leads the largest shared benchmark signal on SWE-bench Verified by 1.8 points.
  • Grok 4 has the lower cheapest tracked output price at $2.50/1M tokens.
  • Local decision data tags Grok 4 for Coding, RAG, and Agents.

Monthly cost at traffic

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

Lower estimate Grok 4

GPT-5

$3,500

Cheapest tracked route/tier: Replicate API

Grok 4

$1,625

Cheapest tracked route/tier: xAI Console

Estimated monthly gap: $1,875. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

GPT-5 -> Grok 4
  • Provider overlap exists on OpenRouter and Replicate API; start route-level A/B tests there.
  • Grok 4 is $7.50/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
Grok 4 -> GPT-5
  • Provider overlap exists on Replicate API and OpenRouter; start route-level A/B tests there.
  • GPT-5 is $7.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.

Specs

Specification
Released2025-08-072025-07-09
Context window400k256k
Parameters
Architecturedecoder onlydecoder only
LicenseProprietaryProprietary
Knowledge cutoff2024-09-

Pricing and availability

Pricing attributeGPT-5Grok 4
Input price$1.25/1M tokens$1.25/1M tokens
Output price$10/1M tokens$2.50/1M tokens
Providers

Capabilities

CapabilityGPT-5Grok 4
VisionYesYes
MultimodalYesYes
ReasoningYesYes
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionYesYes
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkGPT-5Grok 4
SWE-bench Verified74.976.7
Aider Polyglot88.079.6

Deep dive

On shared benchmark coverage, SWE-bench Verified has GPT-5 at 74.9 and Grok 4 at 76.7, with Grok 4 ahead by 1.8 points; Aider Polyglot has GPT-5 at 88 and Grok 4 at 79.6, with GPT-5 ahead by 8.4 points. The largest visible gap is 8.4 points on Aider Polyglot, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.

The capability footprint is close: both models cover vision, multimodal input, reasoning mode, function calling, and tool use. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.

For cost, GPT-5 lists $1.25/1M input and $10/1M output tokens on the cheapest tracked provider, while Grok 4 lists $1.25/1M input and $2.50/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok 4 lower by about $2.25 per million blended tokens. Availability is 4 providers versus 4, so concentration risk also matters.

Choose GPT-5 when coding workflow support and larger context windows are central to the workload. Choose Grok 4 when coding workflow support 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, GPT-5 or Grok 4?

GPT-5 supports 400k tokens, while Grok 4 supports 256k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.

Which is cheaper, GPT-5 or Grok 4?

Grok 4 is cheaper on tracked token pricing. GPT-5 costs $1.25/1M input and $10/1M output tokens. Grok 4 costs $1.25/1M input and $2.50/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is GPT-5 or Grok 4 open source?

GPT-5 is listed under Proprietary. Grok 4 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, GPT-5 or Grok 4?

Both GPT-5 and Grok 4 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, GPT-5 or Grok 4?

Both GPT-5 and Grok 4 expose multimodal input. 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.

Where can I run GPT-5 and Grok 4?

GPT-5 is available on Replicate API, OpenRouter, OpenAI API, and Vercel AI Gateway. Grok 4 is available on Microsoft Foundry, OpenRouter, Replicate API, and xAI Console. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-22. Data sourced from public model cards and provider documentation.