400K long context
Hold larger inputs and longer histories—review repos, long docs, or multi-step research with less manual chunking.
GPT-5.1
Try itGPT-5.1
GPT-5.1: reliable chat, long context, production workflows
Stable conversational performance with a 400K context window and up to 128K output. Tune reasoning from none through high, alongside GPT-5.2, GPT-5.4, and other models in one LimaxAI workspace.
- 400K context
- 128K max output
- Prompt cache
- Adjustable reasoning
- Tool calling
> context: 400K · output: 128K
// reasoning.effort: medium · stream: on
> cache: prefix hit · cached_tokens: 12.4K
// tools: 3 registered · structured_output: json
Capabilities
Core capabilities (chat)
From public GPT-5.1 materials; streaming, structured output, and cache behavior depend on LimaxAI integration.
128K max output
Generate longer reports, implementations, or structured answers in one pass.
Prompt caching (when supported)
Reuse stable prefixes (system prompts, policies, few-shot examples) to cut repeated processing—if the platform exposes it.
Adjustable reasoning
Balance speed, cost, and depth with none, low, medium, or high reasoning effort.
Function / tool calling
Route structured tool calls into your systems for agents and automation (per chat capabilities).
Streaming
Stream partial tokens for responsive chat UIs and long replies.
GPT family
GPT-5.1 in the family (qualitative)
GPT-5.1 targets economical, stable long-context chat; compare GPT-5.4 / GPT-5.5 for frontier agents.
Public specs evolve; available models follow LimaxAI’s model list.
| Dimension | GPT-5.1 | GPT-5.2 | GPT-5.4 |
|---|---|---|---|
| Context window | 400K | Higher in public materials | ~1.05M |
| Max output | 128K | 128K class | 128K |
| Reasoning tiers | none–high | Varies by release | none–xhigh |
| Positioning | Stable chat · long context | Capability upgrade | Agents · Computer Use |
| When to pick | Cost-sensitive · long threads | Balanced upgrade | Frontier agents |
Use cases
What GPT-5.1 is for
Aligned with public GPT-5.1 positioning; LimaxAI delivers it as chat.
Large-context analysis
Review codebases, long documents, or research threads with fewer manual splits.
Advanced reasoning & planning
Multi-step thinking with configurable reasoning effort for planning, coding help, and decisions.
Cache-friendly prompts
Put static instructions up front and dynamic user data at the end to improve prefix reuse when caching is on.
Pick 5.1 vs 5.2
GPT-5.1 vs GPT-5.2 (qualitative)
Quick intra-family check; billing follows LimaxAI pricing.
| Dimension | GPT-5.1 | GPT-5.2 |
|---|---|---|
| Primary use | Stable production chat · 400K context | Harder tasks · public benchmark story |
| Context | 400K | Typically larger in public specs |
| Cost posture | More economical in the family | Stronger · often pricier |
| Tools / streaming | Supported (per integration) | Supported (per integration) |
| Prefer 5.1 when | Long threads · budget sensitive | You need more frontier performance |
Why LimaxAI
Why use it on LimaxAI
No separate API console—one chat experience across the GPT family and other frontier models.
Switch across GPT family
Compare GPT-5.1, GPT-5.2, and GPT-5.4 on real tasks with unified credits.
Transparent credits
Bill against LimaxAI points rules for straightforward team cost comparisons.
Streaming chat UX
Same streaming pipeline as other chat models for long replies and iteration.
Get started
Get started in three steps
Try GPT-5.1 in LimaxAI chat.
Sign in to LimaxAI
Open Chat and pick GPT-5.1 (or the closest titled entry) from the model list.
Send a test prompt
Start small, then try long context, tool notes, or higher reasoning when the UI offers it.
Iterate and share
Watch usage on the pricing page, then roll the workflow out to your team.
FAQ
FAQ
How large is the GPT-5.1 context window?
Public docs cite 400,000 input tokens and up to 128,000 output tokens. LimaxAI limits follow the model list and gateway rules.
How does prompt caching work?
On supporting API stacks, caching often applies automatically to prompts ≥1,024 tokens with identical prefixes. LimaxAI chat may or may not surface cache fields—check live behavior and docs.
What reasoning effort levels exist?
Public materials list none (default), low, medium, and high. Use lower tiers for latency-sensitive work and higher tiers for deep multi-step reasoning.
Does it support streaming and tools?
GPT-5.1 supports streaming, function calling, and structured output in the OpenAI ecosystem. LimaxAI chat exposes what the current integration enables.
How do I improve cache hit rate?
Keep prefixes identical: static instructions and examples first, dynamic user data last, stable tool definitions. API users may also use prompt_cache_key when available.
How am I billed on LimaxAI?
Follow LimaxAI points rules for the selected chat model—see the pricing page and your usage history, not third-party API list prices.
Try GPT-5.1 in chat
Run a real task on GPT-5.1
Open Chat, pick GPT-5.1, and start with long-document Q&A or stable multi-turn chat.