GLM-4.5 vs GPT-5 nano
A complete head-to-head: pricing, context window, benchmarks, modality coverage, and openness, with a programmatic verdict synthesized from the underlying data.
Updated
GLM-4.5 specs · GPT-5 nano specs- PriceGPT-5 nano
GPT-5 nano publishes pricing ($0.40 / 1M output tokens) while GLM-4.5 does not.
- Context windowGPT-5 nano
GPT-5 nano accepts 400K tokens vs 128K, 3.1× the room for long documents and codebases.
- BenchmarksTie
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores.
- ModalitiesTie
Both handle text, vision.
- OpennessGLM-4.5
GLM-4.5 ships open weights (MIT); GPT-5 nano is API-only.
On balance GPT-5 nano edges ahead, winning 2 of 5 categories against GLM-4.5's 1. GPT-5 nano publishes pricing ($0.40 / 1M output tokens) while GLM-4.5 does not. GPT-5 nano accepts 400K tokens vs 128K, 3.1× the room for long documents and codebases.
No directly comparable public benchmarks are available for both models, check the spec sheets for individual scores. Both target the same set of modalities (text, vision), so the deciding factors are price, context, and raw quality. GLM-4.5 ships open weights (MIT); GPT-5 nano is API-only.
Both shipped within roughly a month of each other in 2025, so they share the same generation of training data and tooling. GLM-4.5 is usually picked for chinese llm and open source llm workloads, while GPT-5 nano sees more deployments in cheapest llm and fastest llm. If pricing matters more than every last benchmark point, run the numbers in the calculator below before committing.
Side-by-side specs
| Spec | GLM-4.5 | GPT-5 nano |
|---|---|---|
| Provider | Other | OpenAI |
| Released | Jul 2025 | Aug 2025 |
| Modalities | text, vision | text, vision |
| Context window | 128K tokens | 400K tokens |
| Max output | , | 128K tokens |
| Input · 1M | Pricing not published | $0.050 / 1M tokens |
| Output · 1M | Pricing not published | $0.40 / 1M tokens |
| Knowledge cutoff | , | 2024-09 |
| Open weights | Yes (MIT) | No |
| API available | Yes | Yes |
Pricing at scale
What you'd actually pay at typical workloads. Numbers come from each model's published per-million-token rates.
- Light usage, 100k in / 50k out per day, vs $0.750
- Heavy usage, 1M in / 500k out per day, vs $7.50
- RAG workload, 5M in / 200k out per day, vs $9.90
Light usage, 100k in / 50k out per day: pricing not directly comparable (one or both models are missing public per-token rates). Heavy usage, 1M in / 500k out per day: pricing not directly comparable (one or both models are missing public per-token rates). RAG workload, 5M in / 200k out per day: pricing not directly comparable (one or both models are missing public per-token rates).
Estimated spend for the listed models at your usage. Numbers are derived from each model's published per-million-token rates.
- GLM-4.5Pricing unavailable
- GPT-5 nano$0.025
Benchmarks compared
Only sourced numbers. Where a benchmark is missing for one model we show the available value rather than fabricating the other.
GLM-4.5 fits when…
- MIT license
- Strong Chinese
- Multimodal
- Self-hosting and on-prem requirements, open weights (MIT).
GPT-5 nano fits when…
- Lowest-cost OpenAI model with vision support
- Fast P99 latency
- Good enough for routing and classification
- Long-context tasks, handles 400K tokens vs 128K for GLM-4.5.
Consider DBRX
Databricks' 132B MoE, a notable 2024 open-weight release tuned for enterprise.
Frequently asked
Is GLM-4.5 or GPT-5 nano cheaper?
Per-token pricing isn't published for at least one of these models, check each model's spec page for current rates.Which has the larger context window?
GPT-5 nano accepts 400K tokens vs 128K for GLM-4.5.Is GLM-4.5 or GPT-5 nano better for coding?
Both GLM-4.5 and GPT-5 nano are competitive on coding benchmarks. See each model's individual spec page for HumanEval and SWE-bench scores where published. For an opinionated pick, consult our Best LLM for Coding ranking.Are either of these models open source?
GLM-4.5 ships open weights (MIT). GPT-5 nano is API-only.When were GLM-4.5 and GPT-5 nano released?
GLM-4.5 was released by Other on 2025-07-28. GPT-5 nano was released by OpenAI on 2025-08-07.
The week's AI launches, in your inbox.
One short email every Friday, new models, leaks, and quietly-shipped APIs you missed.