GLM-5.2 vs o3-pro
GLM-5.2 (2026) and o3-pro (2025) are frontier-tier reasoning models from Zhipu AI and OpenAI. GLM-5.2 ships a 1m-token context window, while o3-pro ships a 200k-token context window. On Google-Proof Q&A, GLM-5.2 leads by 7.2 pts. On pricing, GLM-5.2 costs $1.40/1M input tokens versus $20/1M 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-5.2 is ~1329% cheaper at $1.40/1M; pay for o3-pro only for coding workflow support.
Decision scorecard
Local evidence first| Signal | GLM-5.2 | o3-pro |
|---|---|---|
| Best for | reasoning-heavy apps, tool-calling agents, and long-context analysis | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 1m | 200k |
| Cheapest output | $4.40/1M tokens | $80/1M tokens |
| Provider routes | 1 tracked | 3 tracked |
| Shared benchmarks | Google-Proof Q&A leader | 1 shared |
Decision tradeoffs
- GLM-5.2 holds a shared-benchmark lead on Google-Proof Q&A, ahead by 7.2 points.
- GLM-5.2 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GLM-5.2 has the lower cheapest tracked output price at $4.40/1M tokens.
- Local decision data tags GLM-5.2 for Coding, RAG, and Agents.
- o3-pro has broader tracked provider coverage for fallback and procurement flexibility.
- o3-pro uniquely exposes Vision and Multimodal in local model data.
- Local decision data tags o3-pro 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-5.2
$2,220
Cheapest tracked route/tier: OpenRouter
o3-pro
$36,000
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $33,780. 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.
- o3-pro is $75.60/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- o3-pro adds Vision and Multimodal in local capability data.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- GLM-5.2 is $75.60/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision and Multimodal before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-06-13 | 2025-06-10 |
| Context window | 1m | 200k |
| Parameters | 753B total, 40B active | — |
| Architecture | Mixture of Experts | Decoder Only |
| License | MITOSI-approved | Proprietary |
| Openness | Open source | Proprietary |
| Commercial use | Commercial use: permitted | Commercial use: conditional |
| Knowledge cutoff | - | 2025-08 |
Pricing and availability
| Pricing attribute | GLM-5.2 | o3-pro |
|---|---|---|
| Input price | $1.40/1M tokens | $20/1M tokens |
| Output price | $4.40/1M tokens | $80/1M tokens |
| Providers |
Capabilities
| Capability | GLM-5.2 | o3-pro |
|---|---|---|
| Vision | No | Yes |
| Multimodal | No | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| 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-5.2 | o3-pro |
|---|---|---|
| Google-Proof Q&A | 91.2 | 84.0 |
Deep dive
On shared benchmark coverage, Google-Proof Q&A has GLM-5.2 at 91.2 and o3-pro at 84, with GLM-5.2 ahead by 7.2 points. The largest visible gap is 7.2 points on Google-Proof Q&A, 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 differs most on vision: o3-pro and multimodal input: o3-pro. Both models share reasoning mode, function calling, tool use, and structured outputs, 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, GLM-5.2 lists $1.40/1M input and $4.40/1M output tokens on the cheapest tracked provider, while o3-pro lists $20/1M input and $80/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts GLM-5.2 lower by about $35.70 per million blended tokens. Availability is 1 providers versus 3, so concentration risk also matters.
Choose GLM-5.2 when coding workflow support, larger context windows, and lower input-token cost are central to the workload. Choose o3-pro when coding workflow support and broader provider choice 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, GLM-5.2 or o3-pro?
GLM-5.2 supports 1m tokens, while o3-pro supports 200k 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, GLM-5.2 or o3-pro?
GLM-5.2 is cheaper on tracked token pricing. GLM-5.2 costs $1.40/1M input and $4.40/1M output tokens. o3-pro costs $20/1M input and $80/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is GLM-5.2 or o3-pro open source?
GLM-5.2 is listed under MIT. o3-pro 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, GLM-5.2 or o3-pro?
o3-pro has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, GLM-5.2 or o3-pro?
o3-pro has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run GLM-5.2 and o3-pro?
GLM-5.2 is available on OpenRouter. o3-pro is available on OpenRouter, OpenAI API, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Continue comparing
Last reviewed: 2026-06-16. Data sourced from public model cards and provider documentation.