GPT-4.1 API Release Notes / What's New

OpenAI has released a new series of API models—GPT-4.1, GPT-4.1 mini, and GPT-4.1 nano—that outperform GPT-4o and GPT-4o mini in coding, instruction following, and long-context comprehension. These models introduce a expanded context window of up to 1 million tokens and a refreshed knowledge cutoff of June 2024.

Enhanced Coding Capabilities

GPT-4.1 is designed for high-performance software engineering, showing significant gains in agentic task solving and code editing reliability.

  • Software Engineering Performance: GPT-4.1 scored 54.6% on SWE-bench Verified, a 21.4% absolute improvement over GPT-4o and 26.6% absolute improvement over GPT-4.5.
  • Code Diff Reliability: The model more than doubles GPT-4o's score on Aider's polyglot diff benchmark and exceeds GPT-4.5 by 8% absolute. This allows developers to output only changed lines rather than rewriting entire files, reducing cost and latency.
  • Frontend Development: In head-to-head comparisons, human graders preferred GPT-4.1's generated websites over GPT-4o's 80% of the time.
  • Reduced Noise: Internal evaluations show that extraneous edits on code dropped from 9% with GPT-4o to 2% with GPT-4.1.

Improved Instruction Following and Reliability

GPT-4.1 demonstrates higher reliability across various complex instruction categories, including format following (XML, YAML, Markdown), negative instructions, ordered instructions, and ranking.

  • Benchmark Gains: GPT-4.1 scored 38.3% on Scale's MultiChallenge benchmark (a 10.5% absolute increase over GPT-4o) and 87.4% on IFEval (compared to 81.0% for GPT-4o).
  • Multi-turn Coherence: The model is trained to better retrieve information from past messages, improving coherence in deep conversations.
  • Real-world Application: Early testers, such as Blue J, reported a 53% increase in accuracy on challenging real-world tax scenarios compared to GPT-4o. Hex reported a nearly 2x improvement on their most challenging SQL evaluation set.

Long-Context Understanding and Reasoning

All models in the GPT-4.1 family now support a context window of 1 million tokens, significantly increasing the capacity for processing large codebases or extensive document sets.

  • Retrieval Accuracy: In "needle in a haystack" evaluations, GPT-4.1, mini, and nano consistently retrieved information accurately across all positions up to 1 million tokens.
  • Complex Reasoning: To evaluate multi-hop reasoning, OpenAI introduced the Graphwalks dataset. GPT-4.1 achieved 61.7% accuracy on this benchmark, matching OpenAI o1 and exceeding GPT-4o.
  • Multi-Round Coreference: OpenAI also open-sourced the OpenAI-MRCR eval, where GPT-4.1 outperforms GPT-4o at context lengths up to 128K and maintains strong performance up to 1 million tokens.
  • Enterprise Impact: Thomson Reuters reported a 17% improvement in multi-document review accuracy for CoCounsel, while Carlyle saw 50% better retrieval from very large, dense documents.

Model Family Tiers and Performance

OpenAI has introduced three distinct tiers to balance intelligence, latency, and cost:

  • GPT-4.1: The flagship model for the most complex tasks, offering the highest intelligence and the largest context window.
  • GPT-4.1 mini: A high-efficiency model that matches or exceeds GPT-4o in intelligence evals while reducing latency by nearly half and reducing cost by 83%.
  • GPT-4.1 nano: The fastest and cheapest model available, scoring 80.1% on MMLU and 50.3% on GPQA. It is optimized for low-latency tasks like classification and autocompletion.

Vision and Multimodal Capabilities

GPT-4.1 provides advanced image understanding, with GPT-4.1 mini frequently beating GPT-4o on image benchmarks. The model also sets a new state-of-the-art in long-video understanding, scoring 72.0% on the Video-MME (long, no subtitles) category, a 6.7% absolute improvement over GPT-4o.

Pricing and Availability

GPT-4.1 models are available via the API. GPT-4.5 Preview will be deprecated on July 14, 2025.

Model Input (per 1M) Cached Input (per 1M) Output (per 1M) Blended Pricing
GPT-4.1 $2.00 $0.50 $8.00 $1.84
GPT-4.1 mini $0.40 $0.10 $1.60 $0.42
GPT-4.1 nano $0.10 $0.025 $0.40 $0.12

Key Pricing Updates:

  • Prompt Caching: The discount for repeated context has increased to 75% (from 50%).
  • Long Context: Requests up to 1 million tokens are offered at no additional cost beyond standard per-token rates.
  • Batch API: A 50% discount is available for use via the Batch API.

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