GPT-5 Nano vs Seed-OSS-36B-Instruct
GPT-5 Nano comes out ahead, 70 to 60 on our weighted score, and it is the cheaper option too.
- Our pick
OpenAI
GPT-5 Nano
70/100- ECI139.3
- Price$0.05 / $0.40
- Context400K
ByteDance Seed
Seed-OSS-36B-Instruct
60/100- ECI—
- Price—
- Context524K
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Make it a three-way comparison.
GPT-5 Nano is our pick
GPT-5 Nano is the better all-round choice, scoring 70/100 against Seed-OSS-36B-Instruct (60). It leads on capability and inputs & features. Seed-OSS-36B-Instruct wins on context window. The score weighs capability 67%, inputs & features 20%, context window 13%. Capability uses the average of shared benchmarks (GPQA Diamond and OTIS Mock AIME 2024–2025), because Seed-OSS-36B-Instruct has no Capabilities Index score yet.
- CapabilityGPT-5 NanoShared benchmarks: GPT-5 Nano 75.3% · Seed-OSS-36B-Instruct 69.5%
- Lowest priceGPT-5 NanoGPT-5 Nano $0.138 per 1M tokens (3:1 blend) · Seed-OSS-36B-Instruct unpriced
- Longest contextSeed-OSS-36B-InstructSeed-OSS-36B-Instruct 524,288 · GPT-5 Nano 400,000 tokens
- Widest inputsGPT-5 NanoGPT-5 Nano: Text, Images · Seed-OSS-36B-Instruct: Text
- Self-hostingSeed-OSS-36B-InstructPublishes downloadable weights (Apache 2.0)
| Measure | Weight | GPT-5 Nano | Seed-OSS-36B-Instruct |
|---|---|---|---|
| CapabilityShared benchmarks | 67% | 75 | 70 |
| Inputs & features | 20% | 70 | 35 |
| Context window | 13% | 44 | 49 |
| Overall | 100% | 70/100 | 60/100 |
Left out because at least one model lacks the data: price. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | ||
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 139.3 | — |
| ECI rank | #116 of 165 | — |
| GPQA DiamondGraduate-level science questions | 69.4% | 71.5% (best) |
| FrontierMath Tiers 1–3Research-level mathematics | 20.0% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 81.1% (best) | 67.5% |
| SimpleQA VerifiedShort factual questions | 11.7% | — |
| Price per million tokens | ||
| Input | $0.05 | — |
| Output | $0.40 | — |
| Cached input | $0.005 | — |
| Blended (3:1) | $0.138 | — |
| Long-context rate | Same rate | — |
| Price source | Official OpenAI API | — |
| Limits | ||
| Context window | 400,000 tokens | 524,288 tokens (best) |
| Max output | 128,000 tokens | 524,288 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | No |
| PDFs | No | No |
| Audio | No | No |
| Video | No | No |
| Reasoning | Yesminimal · low · medium · high | Yes |
| Tool calling | Yes | Yes |
| Structured output | Yes | No |
| Availability | ||
| Weights | Proprietary | OpenApache 2.0 |
| API model ID | gpt-5-nano | — |
| API providers | 30 | — |
| Released | Aug 7, 2025 | Aug 20, 2025 |
| Knowledge cutoff | May 30, 2024 | Jul 2024 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
GPT-5 Nano$1.30
Seed-OSS-36B-Instruct—
Which should you choose?
Which is better: GPT-5 Nano or Seed-OSS-36B-Instruct?
GPT-5 Nano is the better all-round choice, scoring 70/100 against Seed-OSS-36B-Instruct (60). It leads on capability and inputs & features. Seed-OSS-36B-Instruct wins on context window. The score weighs capability 67%, inputs & features 20%, context window 13%. Capability uses the average of shared benchmarks (GPQA Diamond and OTIS Mock AIME 2024–2025), because Seed-OSS-36B-Instruct has no Capabilities Index score yet.
Which is cheaper, GPT-5 Nano or Seed-OSS-36B-Instruct?
GPT-5 Nano is cheaper at $0.05 input / $0.40 output per million tokens (official OpenAI API price). . At a typical mix of three input tokens to one output token, that is $0.138 per million tokens for GPT-5 Nano versus . Seed-OSS-36B-Instruct has no published per-token price.
Which scores higher on benchmarks?
Not every model here has a Capabilities Index score, so we compare the average of shared benchmarks (GPQA Diamond and OTIS Mock AIME 2024–2025): GPT-5 Nano 75.3% and Seed-OSS-36B-Instruct 69.5%. On individual benchmarks: GPQA Diamond — Seed-OSS-36B-Instruct 71.5%, GPT-5 Nano 69.4%; OTIS Mock AIME 2024–2025 — GPT-5 Nano 81.1%, Seed-OSS-36B-Instruct 67.5%.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5 Nano and Seed-OSS-36B-Instruct yet, so there is no like-for-like coding score. On overall capability, GPT-5 Nano leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.
Which has the bigger context window?
Seed-OSS-36B-Instruct has the largest context window at 524,288 tokens, against 400,000 for GPT-5 Nano. Maximum output per response: GPT-5 Nano up to 128,000, Seed-OSS-36B-Instruct up to 524,288 tokens.
Which can read images, PDFs, audio or video?
GPT-5 Nano accepts text and images; Seed-OSS-36B-Instruct accepts text. GPT-5 Nano handles the widest range of inputs.
Are any of these open source?
Seed-OSS-36B-Instruct publishes its weights (Apache 2.0) and can be self-hosted; GPT-5 Nano is proprietary.
Which is newer?
Seed-OSS-36B-Instruct is the newest, released Aug 20, 2025. GPT-5 Nano came out Aug 7, 2025. Knowledge cutoff: GPT-5 Nano May 30, 2024, Seed-OSS-36B-Instruct Jul 2024.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Nov 2, 2026.