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GPT-5.5 Pro openai
Release timeline
Stages observed by the nightly radar: announced → API only → weights public → served by third parties. Each entry carries the source it was seen at.
- 2026-04-24 · API only source seeded from the earliest dated observation when first seen · observed 2026-10-07 20:20 UTC
Description
GPT-5.5 Pro is OpenAI’s high-capability model optimized for deep reasoning and accuracy on complex, high-stakes workloads. It features a 1M+ token context window (922K input, 128K output) with support for...
via OpenRouter listing · observed 2026-10-24 21:26 UTC. The listing text is the provider's own description, not an assessment.
Where to run 1 providers · 2 endpoints
Hosted endpoints observed for GPT-5.5 Pro, sorted by input price (USD per million tokens). Each row names its observer and date; prices change daily, so check the source before quoting. Cheapest observed input price: $15.00/M.
| Provider | Model ref | Context | Quant | $/M in | $/M out | tok/s | TTFT | Tools | Status | Observed |
|---|---|---|---|---|---|---|---|---|---|---|
| OpenAI openrouter | openai/gpt-5.5-pro | 1.0M | unknown | $15.00 | $90.00 | — | — | yes | live | 2026-10-24 |
| OpenAI openrouter | openai/gpt-5.5-pro | 1.0M | unknown | $30.00 | $180.00 | — | — | yes | live | 2026-10-24 |
No third-party providers observed beyond the lab's own endpoints.
Facts
| Context length | 1,050,000 tokens (1.0M) · OpenRouter listing |
|---|---|
| Modalities | file + image + text → text |
| Max completion tokens | 128,000 |
| Knowledge cutoff | 2025-12-01 |
| Supported parameters | include_reasoning, max_tokens, reasoning, reasoning_effort, response_format, seed, structured_outputs, tool_choice, tools, verbosity |
| Openness | Closed weights · closed lab |
| Stage | API only |
| Confidence | medium |
| Pricing (USD per M tokens) |
in $30.00 · out $180.00 OpenRouter list price (cheapest live endpoint) · source · observed 2026-10-24 21:26 UTC |
Open alternatives 5
Nearest open-weights models by modality, context and price on this watch list. Not a quality ranking.
| Model | Org | Params | Context | $/M in | License | Why it is here |
|---|---|---|---|---|---|---|
| Qwen3.5-4B | Qwen | 4.66B | 256K | — | apache-2.0 | vision input |
| Llama-3.2-11B-Vision-Instruct | meta-llama | 10.7B | — | — | llama3.2 | vision input |
| Qwen3-VL-4B-Instruct | Qwen | 4.44B | 256K | — | apache-2.0 | vision input |
| Qwen3-VL-2B-Instruct | Qwen | 2.13B | 256K | — | apache-2.0 | vision input |
| gemma-4-E4B-it | 8.00B | 128K | — | apache-2.0 | vision input |
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Sources
- openrouter openai/gpt-5.5-pro · observed 2026-10-24 21:26 UTC
Radar run: 2026-10-25 06:51 UTC · Last verified 2026-10-25 06:51 UTC