GLM-5.1 vs Grok 4
GLM-5.1 (2026) and Grok 4 (2025) are frontier-tier reasoning models from Zhipu AI and xAI. GLM-5.1 ships a 200k-token context window, while Grok 4 ships a 256k-token context window. On Google-Proof Q&A, Grok 4 leads by 1.3 pts. On pricing, GLM-5.1 costs $1.05/1M input tokens versus $1.25/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
GLM-5.1 is safer overall; choose Grok 4 when coding workflow support matters.
Decision scorecard
Local evidence first| Signal | GLM-5.1 | Grok 4 |
|---|---|---|
| Best for | reasoning-heavy apps, tool-calling agents, and provider-routed production | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 200k | 256k |
| Cheapest output | $3.50/1M tokens | $2.50/1M tokens |
| Provider routes | 5 tracked | 4 tracked |
| Shared benchmarks | 3 shared | Google-Proof Q&A leader |
Decision tradeoffs
- GLM-5.1 holds a shared-benchmark lead on AIME 2025, ahead by 3.6 points.
- GLM-5.1 has broader tracked provider coverage for fallback and route flexibility.
- Local decision data tags GLM-5.1 for Coding, RAG, and Agents.
- Grok 4 holds a shared-benchmark lead on Google-Proof Q&A, ahead by 1.3 points.
- Grok 4 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Grok 4 has the lower cheapest tracked output price at $2.50/1M tokens.
- Grok 4 uniquely exposes Vision and Multimodal in local model data.
- 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.
GLM-5.1
$1,715
Cheapest tracked route/tier: OpenRouter
Grok 4
$1,625
Cheapest tracked route/tier: xAI Console
Estimated monthly gap: $90.00. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok 4 is $1/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Grok 4 adds Vision and Multimodal in local capability data.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- GLM-5.1 is $1/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Vision and Multimodal before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-04-07 | 2025-07-09 |
| Context window | 200k | 256k |
| Parameters | 754B total, 40B active | — |
| Architecture | Mixture of Experts | Decoder Only |
| License | MITOSI-approved | Proprietary |
| Openness | Open source | Proprietary |
| Weights | Available | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: permitted | Commercial use: conditional |
| Knowledge cutoff | 2025-11 | - |
Pricing and availability
| Pricing attribute | GLM-5.1 | Grok 4 |
|---|---|---|
| Input price | $1.05/1M tokens | $1.25/1M tokens |
| Output price | $3.50/1M tokens | $2.50/1M tokens |
| Providers |
Capabilities
| Capability | GLM-5.1 | Grok 4 |
|---|---|---|
| Vision | No | Yes |
| Multimodal | No | Yes |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | GLM-5.1 | Grok 4 |
|---|---|---|
| Google-Proof Q&A | 86.2 | 87.5 |
| AIME 2025 | 95.3 | 91.7 |
| Humanity's Last Exam | 31.0 | 25.4 |
Continue comparing
Popular comparisons for GLM-5.1
Popular comparisons for Grok 4
Last reviewed: 2026-07-10. Data sourced from public model cards and provider documentation.