GPT-5.5
openai/gpt-5.5-2026-04-23The GPT-5.5 reasoning flagship
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Playground catalog rates, including your 5% Free-plan fee. Included usage applies first, then prepaid credits. Cached tokens and tools can have separate charges. Direct chat-completions routing is not currently listed for this exact model; use its saved agent ID with the Agents API.
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Playground
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Model capabilities below describe the underlying model. Available playground features depend on its provider.
API
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Direct chat-completions routing is not listed for this exact model. Create a saved agent with this model and call it using the Agents API.
Provider price + a transparent platform fee
| Rate | Provider baseline | Free plan · 5% fee | Paid plan · 4% fee |
|---|---|---|---|
| Input / 1M tokens | $5 | $5.25 | $5.2 |
| Output / 1M tokens | $30 | $31.5 | $31.2 |
Legacy chat image rates use the catalog baseline. The dedicated image playground shows separate estimates and settles the provider’s metered usage. API rates are current routing ceilings; final API charges use provider-reported cost plus your fee. Cheapest routing compares eligible OpenRouter and Cheaper Inference rates for the same model; savings are not guaranteed. Cached input or other provider charges may differ. Compare all model rates and verified discounts →
How your plan pays for usage
API and playground share one included allowance. Usage including the fee draws from that allowance first, then your prepaid credits. Plans bill monthly; included usage resets weekly: Free $1, Starter $5, Growth $25, Scale $50.
A $1 provider charge becomes $1.05 on Free or $1.04 on a paid plan before included usage is applied. Plan eligibility still applies in the playground.
Free models and limits
Zero-cost models stay $0, including the fee, and do not consume your dollar allowance. Free accounts can make 1,000 free-model API requests per calendar month, resetting in UTC. Admitted requests count even if the provider fails.
Free includes 20 API requests/minute and 6 playground messages/minute. Paid plans raise these limits. See plan limits.
Before a text API request, Gizmo temporarily reserves included usage and, if necessary, prepaid credit for the model’s full context plus your maximum output. Image jobs reserve twice their displayed estimate. Unused funds return after metering. This hold can exceed the final charge; unconfirmed usage remains marked pending.
Overview
GPT-5.5 is OpenAI’s frontier model designed for complex professional workloads, building on GPT-5.4 with stronger reasoning, higher reliability, and improved token efficiency on hard tasks. It features a 1M+ token context window (922K input, 128K output) with support for text and image inputs, enabling large-scale reasoning, coding, and multimodal workflows within a single system.
Strengths
- Deep reasoning
- Strong coding
Best for
Benchmarks
Artificial Analysis indices independent, 0–100
Design Arena head-to-head, human-voted
| Category | Elo | Win rate | Rank |
|---|---|---|---|
| agenticslides (agent) | 1150 | 43.5% | #6 |
| agenticslides(python-pptx) (agent) | 1155 | 45.2% | #6 |
| pptxslides (agent) | 1157 | 45.3% | #6 |
| agentichtmlslides (agent) | 1084 | 34.2% | #8 |
| agenticslides(html) (agent) | 1077 | 33.2% | #8 |
| godotgamedev (agent) | 1212 | 52.4% | #9 |
| SVG | 1265 | 57.6% | #9 |
| Game dev | 1323 | 59.3% | #10 |
Capabilities
Reasoning is on by default with effort levels xhigh · high · medium · low · none (default medium).
Sampling controls: max_tokens. Defaults: top_k null, top_p null, temperature null, presence_penalty null, frequency_penalty null, repetition_penalty null.
Requests pass through the provider’s content moderation.
Pricing on Gizmo
These are provider baseline rates before Gizmo’s 5% Free-plan or 4% paid-plan fee. Your included usage covers charges first; overage uses prepaid credits. See the fee-inclusive comparison above.
Provider baseline rates
- Input
- $5 / 1M
- Cached input
- $0.5 / 1M
- Output
- $30 / 1M
- Web search
- $0.01 / call
Examples before the platform fee
- Typical chat turn
- $0.025 2k in · 500 out
- $1 of input
- ≈ 200k tokens
- $1 of output
- ≈ 33k tokens
- Full context, once
- $5.25
Providers and pricing
One way to run GPT-5.5 on Gizmo.
| Provider | Route | Input / 1M | Output / 1M | Context | Uptime 24h |
|---|---|---|---|---|---|
| OpenAILowest price | Direct | $5.00 | $30.00 | 1.05M | 100% |
Rates are each provider’s, per million tokens, before Gizmo’s 5% (Free) or 4% (paid) fee. “Cheapest” routing starts at the top of this list; “Fastest” starts with the model’s maker.
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Run GPT-5.5 in under a minute
Create your account
Sign up with just an email. Start on the free tier with no card, or pick a paid plan for a bigger weekly allowance and $25 in bonus credits.
Your agent is ready
GPT-5.5 is preselected as the brain of your first agent. Give it a name and a system prompt, or keep the defaults.
Chat, research, create
Live web research and image generation are built in. Every reply shows what it cost, and you can switch models anytime.