Choose DeepSeek: DeepSeek V3.1 Terminus (exacto) if…
No advantage on the data we track — pick it for provider preference or output quality on your own prompts.
OpenAI: gpt-oss-20b (batch) comes out ahead on the data we track: 1 advantage and none for DeepSeek: DeepSeek V3.1 Terminus (exacto).
| Spec | DeepSeek: DeepSeek V3.1 Terminus (exacto) | OpenAI: gpt-oss-20b (batch) |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Input price (per 1M tokens) | $0.21 | $0.02 |
| Output price (per 1M tokens) | $0.79 | $0.11 |
| Blended price (3:1 input/output) | $0.35 | $0.05 |
| Cheaper than … of all models we track | 61% | 87% |
| Context window | 164K tokens (~246 pages) | 131K tokens (~197 pages) |
| Larger context than … of all models | 36% | 23% |
| Max output per response | n/a | 118K tokens (~88,500 words) |
| Input types | text | text |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2025-09-22 | 2025-08-05 |
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
| Workload (per month) | DeepSeek: DeepSeek V3.1 Terminus (exacto) | OpenAI: gpt-oss-20b (batch) | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $31.55 | $4.04 | OpenAI: gpt-oss-20b (batch) saves $27.51 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $33.10 | $4.00 | OpenAI: gpt-oss-20b (batch) saves $29.10 |
| Coding / tool-using agent 2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens) | $34.68 | $4.22 | OpenAI: gpt-oss-20b (batch) saves $30.46 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $21.54 | $2.59 | OpenAI: gpt-oss-20b (batch) saves $18.95 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $11.29 | $1.31 | OpenAI: gpt-oss-20b (batch) saves $9.98 |
| Capability | DeepSeek: DeepSeek V3.1 Terminus (exacto) | OpenAI: gpt-oss-20b (batch) | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | ✓ Yes | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | ✓ Yes | ✓ Yes | spend extra tokens thinking before answering hard problems |
| Image input | — | — | read screenshots, charts and scanned pages |
| Audio input | — | — | take speech or audio directly |
| File / PDF input | — | — | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | — | — | answer from live web results |
| Seed (reproducible sampling) | ✓ Yes | ✓ Yes | repeat a generation for tests and evals |
| Log-probabilities | — | — | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
| Date | Model | Input / 1M | Output / 1M |
|---|---|---|---|
| 2026-09-23 | OpenAI: gpt-oss-20b (batch) | $0.02 | $0.11 |
No advantage on the data we track — pick it for provider preference or output quality on your own prompts.
OpenAI: gpt-oss-20b (batch) comes out ahead on the data we track: 1 advantage and none for DeepSeek: DeepSeek V3.1 Terminus (exacto).
OpenAI: gpt-oss-20b (batch) is cheaper: $0.05 vs $0.35 per 1M tokens at a typical 3:1 input/output mix, 87% less. For 50,000 support conversations a month that is $4.04 against $31.55.
DeepSeek: DeepSeek V3.1 Terminus (exacto) costs $0.21 per 1M input tokens and $0.79 per 1M output tokens; OpenAI: gpt-oss-20b (batch) costs $0.02 input and $0.11 output. Output tokens are billed separately, so long answers shift the gap.
DeepSeek: DeepSeek V3.1 Terminus (exacto): 164K tokens, about 246 pages, against 131K (about 197 pages) for OpenAI: gpt-oss-20b (batch).
Tool calling — DeepSeek: DeepSeek V3.1 Terminus (exacto): yes, OpenAI: gpt-oss-20b (batch): yes. JSON-schema structured output — DeepSeek: DeepSeek V3.1 Terminus (exacto): yes, OpenAI: gpt-oss-20b (batch): yes.
Neither accepts image input — both are text-in models.
No free variant is listed for either; both are pay-per-token.
DeepSeek: DeepSeek V3.1 Terminus (exacto) was listed on 2025-09-22; OpenAI: gpt-oss-20b (batch) on 2025-08-05.
DeepSeek: DeepSeek V3.1 Terminus (exacto): price unchanged since we started tracking it on 2026-03-10. OpenAI: gpt-oss-20b (batch): input price cut 52% ($0.05 → $0.02/1M), output price cut 44% ($0.20 → $0.11/1M) on 2026-09-23.
DeepSeek-V3.1 Terminus is an update to [DeepSeek V3.1](/deepseek/deepseek-chat-v3.1) that maintains the model's original capabilities while addressing issues reported by users, including language consistency and agent capabilities, further optimizing the model's performance in coding and search agents. It is a large hybrid reasoning model (671B parameters, 37B active) that supports both thinking and non-thinking modes. It extends the DeepSeek-V3 base with a two-phase long-context training process, reaching up to 128K tokens, and uses FP8 microscaling for efficient inference. Users can control the reasoning behaviour with the `reasoning` `enabled` boolean. [Learn more in our docs](https://openrouter.ai/docs/use-cases/reasoning-tokens#enable-reasoning-with-default-config) The model improves tool use, code generation, and reasoning efficiency, achieving performance comparable to DeepSeek-R1 on difficult benchmarks while responding more quickly. It supports structured tool calling, code agents, and search agents, making it suitable for research, coding, and agentic workflows.
Full DeepSeek: DeepSeek V3.1 Terminus (exacto) specs →gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license. It uses a Mixture-of-Experts (MoE) architecture with 3.6B active parameters per forward pass, optimized for...
Full OpenAI: gpt-oss-20b (batch) specs →