Claude Mythos Preview vs GLM-5
Claude Mythos Preview (2026) and GLM-5 (2026) are frontier-tier reasoning models from Anthropic and Zhipu AI. Claude Mythos Preview ships a 1M-token context window, while GLM-5 ships a 200k-token context window. On SWE-bench Verified, Claude Mythos Preview leads by 16.1 pts. On pricing, GLM-5 costs $0.6/1M input tokens versus $25/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
GLM-5 is ~4067% cheaper at $0.6/1M; pay for Claude Mythos Preview only for coding workflow support.
Decision scorecard
Local evidence first| Signal | Claude Mythos Preview | GLM-5 |
|---|---|---|
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 1M | 200k |
| Cheapest output | $125/1M tokens | $2.08/1M tokens |
| Provider routes | 2 tracked | 5 tracked |
| Shared benchmarks | SWE-bench Verified leader | 2 rows |
Decision tradeoffs
- Claude Mythos Preview leads the largest shared benchmark signal on SWE-bench Verified by 16.1 points.
- Claude Mythos Preview has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Claude Mythos Preview uniquely exposes Vision, Multimodal, and Code execution in local model data.
- Local decision data tags Claude Mythos Preview for Coding, RAG, and Agents.
- GLM-5 has the lower cheapest tracked output price at $2.08/1M tokens.
- GLM-5 has broader tracked provider coverage for fallback and procurement flexibility.
- Local decision data tags GLM-5 for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output prices on this page.
Claude Mythos Preview
$51,250
Cheapest tracked route: Anthropic
GLM-5
$1,000
Cheapest tracked route: OpenRouter
Estimated monthly gap: $50,250. Batch, cache, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for Claude Mythos Preview and GLM-5; plan for SDK, billing, or endpoint changes.
- GLM-5 is $123/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Multimodal, and Code execution before moving production traffic.
- No overlapping tracked provider route is sourced for GLM-5 and Claude Mythos Preview; plan for SDK, billing, or endpoint changes.
- Claude Mythos Preview is $123/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Claude Mythos Preview adds Vision, Multimodal, and Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-04-07 | 2026-02-11 |
| Context window | 1M | 200k |
| Parameters | — | 744B total, 40B active |
| Architecture | decoder only | mixture of experts |
| License | Proprietary | MIT |
| Knowledge cutoff | 2025-12 | - |
Pricing and availability
| Pricing attribute | Claude Mythos Preview | GLM-5 |
|---|---|---|
| Input price | $25/1M tokens | $0.6/1M tokens |
| Output price | $125/1M tokens | $2.08/1M tokens |
| Providers |
Capabilities
| Capability | Claude Mythos Preview | GLM-5 |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
Benchmarks
| Benchmark | Claude Mythos Preview | GLM-5 |
|---|---|---|
| SWE-bench Verified | 93.9 | 77.8 |
| τ-bench | 89.2 | 82.1 |
Deep dive
On shared benchmark coverage, SWE-bench Verified has Claude Mythos Preview at 93.9 and GLM-5 at 77.8, with Claude Mythos Preview ahead by 16.1 points; τ-bench has Claude Mythos Preview at 89.2 and GLM-5 at 82.1, with Claude Mythos Preview ahead by 7.1 points. The largest visible gap is 16.1 points on SWE-bench Verified, 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: Claude Mythos Preview, multimodal input: Claude Mythos Preview, and code execution: Claude Mythos Preview. 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, Claude Mythos Preview lists $25/1M input and $125/1M output tokens, while GLM-5 lists $0.6/1M input and $2.08/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts GLM-5 lower by about $53.96 per million blended tokens. Availability is 2 providers versus 5, so concentration risk also matters.
Choose Claude Mythos Preview when coding workflow support and larger context windows are central to the workload. Choose GLM-5 when provider fit, lower input-token cost, 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, Claude Mythos Preview or GLM-5?
Claude Mythos Preview supports 1M tokens, while GLM-5 supports 200k 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 Mythos Preview or GLM-5?
GLM-5 is cheaper on tracked token pricing. Claude Mythos Preview costs $25/1M input and $125/1M output tokens. GLM-5 costs $0.6/1M input and $2.08/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Claude Mythos Preview or GLM-5 open source?
Claude Mythos Preview is listed under Proprietary. GLM-5 is listed under MIT. 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 Mythos Preview or GLM-5?
Claude Mythos Preview 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.
Which is better for multimodal input, Claude Mythos Preview or GLM-5?
Claude Mythos Preview 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 Claude Mythos Preview and GLM-5?
Claude Mythos Preview is available on Anthropic and Microsoft Foundry. GLM-5 is available on Fireworks AI, OpenRouter, Together AI, GCP Vertex AI, and NVIDIA NIM. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-16. Data sourced from public model cards and provider documentation.