Where is the GPT-4.1 documentation?

The GPT-4.1 documentation on OpenRouter includes the Quasar Alpha and Optimus Alpha Reveal blog post. The quickstart covers API keys and your first request, and the API reference lists every parameter.

How much does GPT-4.1 cost?

GPT-4.1 costs $2.00/M input tokens and $8.00/M output tokens, with separate rates for Cache Read at $0.50/M tokens.

What is the context length of GPT-4.1?

GPT-4.1 has a 1,047,576 token context window.

Does GPT-4.1 support tool calling and structured outputs?

Yes. GPT-4.1 accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.

What inputs and outputs does GPT-4.1 support?

GPT-4.1 accepts images, text, and files such as PDFs as input and returns text.

Which providers serve GPT-4.1?

GPT-4.1 is served by 2 providers on OpenRouter: Azure and OpenAI. Requests are routed to the best available provider, with automatic failover to the others, and you can pin or exclude providers with provider routing.

When was GPT-4.1 released?

GPT-4.1 was released on April 14, 2025. Its knowledge cutoff is June 30, 2024.

OpenAI: GPT-4.1

openai/gpt-4.1

Compare

GPT-4.1 is a flagship large language model optimized for advanced instruction following, real-world software engineering, and long-context reasoning. It supports a 1 million token context window and outperforms GPT-4o and GPT-4.5 across coding (54.6% SWE-bench Verified), instruction compliance (87.4% IFEval), and multimodal understanding benchmarks. It is tuned for precise code diffs, agent reliability, and high recall in large document contexts, making it ideal for agents, IDE tooling, and enterprise knowledge retrieval.

Modalities

In / out price

$2 / $8per 1M

Context

1.0M

Released

Apr 14, 2025

Knowledge cutoff

Jun 2024

Providers

Different companies host the same model. OpenRouter routes your request to one of them based on the routing mode you pick: Balanced (price + speed), Nitro (fastest), or Floor (cheapest).

Latency / throughput


	$2.00	$8.00	$0.50	0.84s	93 tok/s	100.00%
	$2.00	$8.00	$0.50	2.87s	81 tok/s	100.00%
Not used in Standard routing:Why these endpoints are not used
	$2.20	$8.80	$0.55	0.47s	125 tok/s	100.00%

Input $2.00Output $8.00
93 tok/s100.00% uptime
Input $2.00Output $8.00
81 tok/s100.00% uptime
Not used in Standard routing:Why these endpoints are not used
Input $2.20Output $8.80
125 tok/s100.00% uptime

Pricing

The average price customers actually pay for this model, next to the prices providers post. Caching and discounts mean the price actually paid is often well below the listed one.

Weighted average

Input

$1.438/M tokens

Output

$8.006/M tokens

GPT-4.1 — Price history

Price history

No effective price data for this selection

	$1.25	$8.00	49.8%	13.3%
	$1.47	$8.00	35.2%	84.3%
Not used in Standard routing:Why these endpoints are not used
	$1.23	$8.80	58.6%	2.4%

Effective in $1.25Effective out $8.00
Token share
13.3%
Effective in $1.47Effective out $8.00
Token share
84.3%
Not used in Standard routing:Why these endpoints are not used
Effective in $1.23Effective out $8.80
Token share
2.4%

Uptime

Uptime is the percentage of the past 3 days that at least one provider was responding to requests. Availability is the percentage of time that inference was successfully served. OpenRouter continuously monitors and uses the next-best provider when one returns an error.

Uptime (3d)

100.00%

Availability (3d)

99.98%

Availability over the last 3 days

Last 72 hours

Availability 99.98%

3 Days Ago2 Days AgoYesterdayNow

Availability over the last 24 hours

OpenRouter Availability

99.96%

Without Routing

99.61%

When an error occurs in an upstream provider, we can recover by routing to another healthy provider, if your request filters allow it. You can access per-provider uptime data programmatically through the Endpoints API. Learn more about our load balancing and provider routing options.

Benchmarks

Scores on standardized evaluations and this model’s own outputs on shared benchmark prompts. Higher percentages are better — and each rank shows where this model lands among the models evaluated on that source.

Benchmark score summary for OpenAI: GPT-4.1 (Artificial Analysis, Design Arena and Vals AI)
Source	Benchmark	Score
Artificial Analysis	GPT-4.1 GPQA Diamond	66.6%
Artificial Analysis	GPT-4.1 HLE	4.2%
Artificial Analysis	GPT-4.1 IFBench	43.0%
Artificial Analysis	GPT-4.1 τ²-Bench Telecom	47.1%
Artificial Analysis	GPT-4.1 AA-LCR	68.3%
Artificial Analysis	GPT-4.1 CritPt	0.0%
Artificial Analysis	GPT-4.1 LiveCodeBench	45.7%
Artificial Analysis	GPT-4.1 Terminal-Bench Hard	13.6%
Artificial Analysis	GPT-4.1 MMLU-Pro	80.6%
Artificial Analysis	GPT-4.1 AIME 2025	34.7%
Artificial Analysis	GPT-4.1 AIME	43.7%
Artificial Analysis	GPT-4.1 MATH-500	91.3%
Design Arena	GPT-4.1 Models Arena 3D Elo	829
Design Arena	GPT-4.1 Models Arena Code Categories Elo	1015
Design Arena	GPT-4.1 Models Arena Data Visualization Elo	1104
Design Arena	GPT-4.1 Models Arena Game Development Elo	1069
Design Arena	GPT-4.1 Models Arena UI Component Elo	990
Design Arena	GPT-4.1 Models Arena Website Elo	1030
Vals AI	GPT 4.1 AIME	39.6%
Vals AI	GPT 4.1 CaseLaw v2	69.9%
Vals AI	GPT 4.1 CorpFin v2	63.1%
Vals AI	GPT 4.1 Finance Agent v1	24.6%
Vals AI	GPT 4.1 GPQA Diamond	65.4%
Vals AI	GPT 4.1 LiveCodeBench	54.7%
Vals AI	GPT 4.1 LegalBench	83.1%
Vals AI	GPT 4.1 MATH 500	87.2%
Vals AI	GPT 4.1 MedQA	91.2%
Vals AI	GPT 4.1 MGSM	87.7%
Vals AI	GPT 4.1 MMLU Pro	80.5%
Vals AI	GPT 4.1 MMMU Pro	72.4%
Vals AI	GPT 4.1 MortgageTax	65.9%
Vals AI	GPT 4.1 TaxEval v2	75.1%
Vals AI	GPT 4.1 Terminal-Bench 2.0	14.6%

Available through EU in-region routing

OpenAI: GPT-4.1 is available through EU in-region routing. Requests sent to eu.openrouter.ai are decrypted in the EU and routed only to shared provider endpoints in Europe (the EU/EEA, the UK, and Switzerland).

Providers in Europe

Azure

Prices in Europe

Azure: $2.20/M tokens input, $8.80/M tokens output

Base URL

https://eu.openrouter.ai/api/v1

Plan

Requires Business or Enterprise. Self-serve on Business: no contract, no monthly minimum. OpenRouter Business for EU in-region routing

Fails closed: if no shared provider endpoint in Europe is available, the request errors instead of leaving the region. Requests served by your own BYOK key go to your deployment’s region, which you control. In-region routing docs

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GPT-6.1 Terra Pro

GPT-6.1 Terra Pro is the same underlying model as GPT-6.1 Terra, served with reasoning.mode set to pro for higher-quality responses on complex tasks.

Cost note: pro mode spends far more reasoning tokens per request, so a typical request costs several times more than the same request on GPT-6.1 Terra and takes much longer to complete. It is intended for hard, high-stakes problems where the extra accuracy justifies the cost. For everyday coding, agentic, and chat workloads, use GPT-6.1 Terra instead.

Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

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GPT-6.1 Terra Pro (batch)

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GPT-6.1 Terra (batch)

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GPT-6 Luna Decisions

GPT-6 Luna Decisions is GPT-6 Luna served through OpenAI's Decisions API. Instead of generating text, it reads the content passed as state (text, JSON, or images) and returns typed, probabilistic answers to named questions in a single request: the probability of yes for a yes/no question (noul), a probability for every option plus the most likely one (choice), or a probability for every level of an ordered rubric plus the expected score (score).

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Text1.1M context$2 / $10

GPT-6.1 Sol (batch)

Text1.1M context$1 / $5

GPT-6 Luna Pro

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Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

Text1.1M context$0.10 / $0.50

GPT-6 Luna Pro (batch)

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Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode

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GPT-6 Luna (batch)

Text1.1M context$0.05 / $0.25

GPT-6 Sol Pro

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Cost note: pro mode spends far more reasoning tokens per request, so a typical request costs several times more than the same request on GPT-6 Sol and takes much longer to complete. It is intended for hard, high-stakes problems where the extra accuracy justifies the cost. For everyday coding, agentic, and chat workloads, use GPT-6 Sol instead.

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GPT-6 Sol

GPT-6 Sol is the cost-efficient high-end model in OpenAI's GPT-6 series, positioned below the flagship GPT-6 Astra and above the fast GPT-6 Luna tier. It is suited for demanding professional work, agentic coding, business workflow automation, and computer use, and is particularly strong at long-horizon software engineering tasks in real codebases. It approaches Astra-level factual reliability at a much lower cost and shares Astra's clearer, more concise communication style in technical and coding conversations.

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GPT-6 Sol (batch)

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GPT Astra Latest

This model always redirects to the latest model in the GPT Astra family.

Text1.1M context

OpenAI: GPT-4.1

Providers