Compact GPT model for low-latency assistance and high-volume workloads
GPT-5.5 Instant by openai is currently listed from a single provider. Its reference price is $5.00 per 1M input tokens and $30.00 per 1M output tokens.
Artificial Analysis rates it 26 on the Intelligence Index, with 39.4 for coding and 16.6 for agentic tasks. Against its lowest blended price of $11.25 per 1M, that is roughly 2 index points per dollar, which is the value ratio the leaderboards rank on. Median output speed is 121 tokens per second, with 0.88s to the first token. Running one task of the Artificial Analysis suite costs about $0.6915, which reflects how many tokens its reasoning consumes rather than the unit price alone.
The context window is 400,000 tokens, with an output limit of 128,000 tokens. It supports reasoning, tool use, and structured output. Accepted input modalities are Text, Image, and PDF. Its training knowledge cuts off at 2025-12-01.
Quality is independently evaluated by Artificial Analysis. Speed/latency are model-level medians.
| Provider | Tier | Input | Output | Cache read | Cache write | Context | Output limit | Status |
|---|---|---|---|---|---|---|---|---|
| ZenMux | Gateway | $5.00 | $30.00 | $0.50 | — | 400,000 | 128,000 |
Sorted by blended price (input×0.75 + output×0.25) asc. The official channel always shows regardless of rank. Whether a gateway's low price is actually usable can't be verified.
Individual evaluations run by Artificial Analysis, on the same reasoning tier as the intelligence score above. Each benchmark has its own task set and harness, so rows are not comparable with one another. The Intelligence Index above draws on a different, newer set of evaluations.