GPT-5.5 vs Nemotron 3 Nano Omni
GPT-5.5 (2026) and Nemotron 3 Nano Omni (2026) are frontier reasoning models from OpenAI and NVIDIA AI. GPT-5.5 ships a 1.05m-token context window, while Nemotron 3 Nano Omni ships a 262k-token context window. On MMLU PRO, GPT-5.5 leads by 16.3 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
GPT-5.5 fits 4x more tokens; pick it for long-context work and Nemotron 3 Nano Omni for tighter calls.
Decision scorecard
Local evidence first| Signal | GPT-5.5 | Nemotron 3 Nano Omni |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | multimodal apps |
| Decision fit | Coding, RAG, and Agents | Long context, Vision, and Classification |
| Context window | 1.05m | 262k |
| Cheapest output | $30/1M tokens | - |
| Provider routes | 4 tracked | 1 tracked |
| Shared benchmarks | MMLU PRO leader | 1 shared |
Decision tradeoffs
- GPT-5.5 holds a shared-benchmark lead on MMLU PRO, ahead by 16.3 points.
- GPT-5.5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-5.5 has broader tracked provider coverage for fallback and procurement flexibility.
- GPT-5.5 uniquely exposes Vision, Reasoning, and Function calling in local model data.
- Local decision data tags GPT-5.5 for Coding, RAG, and Agents.
- Local decision data tags Nemotron 3 Nano Omni for Long context, Vision, and Classification.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
GPT-5.5
$11,500
Cheapest tracked route/tier: OpenAI API 0-272K input tokens
Nemotron 3 Nano Omni
Unavailable
No complete token price in local provider data
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Check replacement coverage for Vision, Reasoning, and Function calling before moving production traffic.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- GPT-5.5 adds Vision, Reasoning, and Function calling in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-04-23 | 2026-04-28 |
| Context window | 1.05m | 262k |
| Parameters | — | 30B |
| Architecture | Decoder Only | MoE + SSM Hybrid |
| License | Proprietary | NVIDIA Open Model |
| Openness | Proprietary | Open weights |
| Commercial use | Commercial use: conditional | Commercial use: permitted |
| Knowledge cutoff | 2025-12 | - |
Pricing and availability
| Pricing attribute | GPT-5.5 | Nemotron 3 Nano Omni |
|---|---|---|
| Input price |
| - |
| Output price |
| - |
| Providers |
Capabilities
| Capability | GPT-5.5 | Nemotron 3 Nano Omni |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | Yes |
| Reasoning | Yes | No |
| Function calling | Yes | No |
| Tool use | Yes | No |
| Structured outputs | Yes | No |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | GPT-5.5 | Nemotron 3 Nano Omni |
|---|---|---|
| MMLU PRO | 88.1 | 71.8 |
Deep dive
On shared benchmark coverage, MMLU PRO has GPT-5.5 at 88.1 and Nemotron 3 Nano Omni at 71.8, with GPT-5.5 ahead by 16.3 points. The largest visible gap is 16.3 points on MMLU PRO, 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: GPT-5.5, reasoning mode: GPT-5.5, function calling: GPT-5.5, tool use: GPT-5.5, structured outputs: GPT-5.5, and code execution: GPT-5.5. Both models share multimodal input, 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.
Pricing coverage is uneven: GPT-5.5 has $5/1M input tokens and Nemotron 3 Nano Omni has no token price sourced yet. Provider availability is 4 tracked routes versus 1. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose GPT-5.5 when coding workflow support, larger context windows, and broader provider choice are central to the workload. Choose Nemotron 3 Nano Omni when provider fit 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, GPT-5.5 or Nemotron 3 Nano Omni?
GPT-5.5 supports 1.05m tokens, while Nemotron 3 Nano Omni supports 262k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Is GPT-5.5 or Nemotron 3 Nano Omni open source?
GPT-5.5 is listed under Proprietary. Nemotron 3 Nano Omni is listed under NVIDIA Open Model. 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, GPT-5.5 or Nemotron 3 Nano Omni?
GPT-5.5 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. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, GPT-5.5 or Nemotron 3 Nano Omni?
Both GPT-5.5 and Nemotron 3 Nano Omni expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Which is better for reasoning mode, GPT-5.5 or Nemotron 3 Nano Omni?
GPT-5.5 has the clearer documented reasoning mode signal in this comparison. If reasoning mode is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run GPT-5.5 and Nemotron 3 Nano Omni?
GPT-5.5 is available on OpenAI API, OpenRouter, Vercel AI Gateway, and AWS Bedrock. Nemotron 3 Nano Omni is available on OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.