gpt-oss-20b
gpt-oss-20b is worth evaluating for rag, agents, and long context when its provider route and context window match the workload.
Use it for
- Teams evaluating rag, agents, and long context
- Workloads that can use a 131k context window
- Buyers comparing 4 tracked provider routes
Do not use it for
- Vision or document-understanding workloads
- Family
- GPT-OSS
- Released
- 2025-08-05
- Context
- 131k
- Parameters
- 20B
- Architecture
- Decoder Only
- Knowledge cutoff
- 2025-08
- Specialization
- general
- Openness
- Open source
- License
- Apache 2.0OSI-approvedCommercial use: permitted
- Weights
- Unknown
- Code
- Unknown
- Training
- Pretrained
Cheapest of 10 routes · Open Inference
About
OpenAI open-weight model with 20 billion parameters. Lightweight, efficient text-only model with reasoning and function calling. Free for self-hosting. Released August 5, 2025.
gpt-oss-20b is an open-source model in the GPT-OSS family. The structured metadata tracks a 131k-token context window, function calling, tool use, and structured outputs. This page tracks provider routes through Cloudflare Workers AI, OpenRouter, Fireworks AI, and 7 more, with the cheapest tracked route listed at free input and free output per 1M tokens. Headline tracked benchmarks include Google-Proof Q&A 68.8.
Top use-case fit: coding, agents, and build tasks
RAG
Included by capability and metadata signals in the decision map.
Agents
Included by capability and metadata signals in the decision map.
Long context
Included by capability and metadata signals in the decision map.
Provider price ladder
Compare all 10Compare API pricing across 4 providers for input and output tokens, batch, and cached reads when available.
| Provider | Input / 1M | Output / 1M | Route |
|---|---|---|---|
| Open Inference | Free | Free | Serverless |
| OpenRouter | $0.030 | $0.140 | Serverless |
| Novita AI | $0.040 | $0.150 | Serverless |
| Vercel AI Gateway | $0.050 | $0.200 | Serverless |
Available via routers & gateways(14)
LiteLLM
GatewayOpen-source Python SDK and proxy server that unifies 100+ LLM APIs behind a single OpenAI-compatible interface, with load balancing, cost tracking, and configurable failover.
OpenRouter
HybridUnified hybrid gateway to 400+ models from 60+ providers via a single OpenAI-compatible API, with optional auto-routing that selects the best model per prompt.
Portkey
GatewayProduction AI gateway routing to 1,600+ LLMs with failover, load balancing, semantic caching, and guardrails; Apache 2.0 core is fully self-hostable with the complete feature set.
AIRouter
RouterCommercial LLM router that analyzes incoming requests and routes to the optimal model for cost/quality/latency via a drop-in OpenAI-compatible API, with a privacy-preserving embedding mode that avoids sending prompt content.
Helicone
GatewayObservability-first AI gateway with routing, caching, rate limiting, and request tracing; Apache 2.0 open-source core with a managed hosted tier for logging and analytics.
Kong AI Gateway
GatewayMulti-LLM AI gateway built on Kong Gateway 3.x, adding semantic routing, load balancing, guardrails, and MCP traffic analytics as plugins over Kong's existing API management platform.
Capabilities
Benchmark peer barsfor RAG
No task-mapped benchmark peers are available for this model yet.
Benchmark scores(1)
| Benchmark | Score | Version | Evaluation | Source |
|---|---|---|---|---|
| Google-Proof Q&A | 68.8 | diamondObserved 2026-04-18 | — | Source |
Migration checks
No linked migration route is available for this model yet.
Rankings & picks(1)
Compare gpt-oss-20b with other models
Comparison and alternatives
Browse all comparisons →Frequently asked questions
What is the context window of gpt-oss-20b?
gpt-oss-20b has a context window of 131k tokens.
How much does gpt-oss-20b cost?
gpt-oss-20b pricing ranges from $0/1M to $0.200/1M input tokens depending on the provider.
When was gpt-oss-20b released?
gpt-oss-20b was released on 2025-08-05.
Which providers offer gpt-oss-20b?
gpt-oss-20b is available from 10 providers: Cloudflare Workers AI, OpenRouter, Fireworks AI, GCP Vertex AI, NVIDIA NIM, GroqCloud, Replicate API, Vercel AI Gateway, Novita AI, Open Inference.
What benchmarks has gpt-oss-20b been tested on?
gpt-oss-20b has been evaluated on 1 benchmark, including Google-Proof Q&A.
Cheapest of 10 routes · Open Inference