GPT-5 Pro: Extended Reasoning for the Hardest, Highest-Stakes Problems
GPT-5 Pro is OpenAI's extended-reasoning variant of GPT-5, positioned above the standard GPT-5 for problems where correctness outweighs speed and cost. It runs at high reasoning effort by default, spending more compute per request to raise accuracy on math, science, and complex professional work. GPT-5 Pro set a new state of the art on GPQA at launch and is delivered through the Responses API. It fits workloads where a single high-quality answer justifies minutes of latency: advanced research, expert-level analysis, and verification of critical outputs.
Access GPT-5 Pro through the AnyAPI.ai unified API
OpenAI's highest-effort reasoning model for hard problems where accuracy matters more than latency or cost.
Modality:
Text
Image
PDF
model ID
openai/gpt-5-pro
Output Speed *
N/A
tok/s
Intelligence Index *
N/A
/ 100
Context Window *
400000
tokens
Input price
90
Anytoken
Output price
720
Anytoken
Performance
Where GPT-5 Pro's Extra Reasoning Effort Pays Off
GPT-5 Pro is built to maximize answer quality on difficult reasoning tasks rather than to serve high-volume traffic. OpenAI reports that with its extended reasoning, GPT-5 Pro set a state of the art on GPQA, scoring 88.4% without tools on this graduate-level science benchmark. The practical meaning is that the model trades latency and cost for a higher chance of a correct answer on problems where errors are expensive. In production this makes it a verification and hard-problem tier: a model you call selectively for high-stakes outputs, not a default endpoint behind interactive user traffic.
Benchmarks
GPT-5 Pro on Science and Math Benchmarks
GPT-5 Pro's headline result is graduate-level science reasoning: OpenAI reports 88.4% on GPQA without tools, the highest in the GPT-5 family at launch. On competition math, independent coverage notes GPT-5 Pro reached a perfect 100% on AIME 2025 when given a Python tool, though tool-assisted math results are not directly comparable to no-tool scores. Broadly, the GPT-5 family established strong marks in math and real-world coding (SWE-bench Verified). Treat GPQA and AIME as near-saturated at the top tier — small gaps between frontier models should not alone drive model selection.
Output Speed
*
N/A
tok/s
Intelligence Index
*
N/A
/ 100
MMLU *
Broad world knowledge and problem-solving
0
%
GPQA *
PhD-level scientific reasoning across physics, biology, chemistry.
0
%
HLE *
Adherence to multi-step structured instructions.
0
%
LiveCodeBench *
Tool-calling reliability in long agentic loops.
0
%
Technical Specifications
What the model supports
GPT-5 Pro accepts text and image input and returns text. It shares the standard GPT-5's 400,000-token context window, with OpenAI documentation listing a large maximum output allocation. The most consequential constraints are architectural: GPT-5 Pro is available only through the Responses API, defaults to and only supports high reasoning effort, and does not support the code interpreter. Because it is designed for hard problems, individual requests can take minutes, and OpenAI recommends background mode to avoid timeouts. Plan around asynchronous request handling rather than synchronous interactive calls.
Verified Specifications —
GPT-5 Pro (Xhigh)
*
Input modalities
Text
Image
PDF
output modalities
Text
Context window
400000
tokens
Maximum output tokens
128000
Reasoning
Yes
Knowledge cutoff
October 2025
Pricing (standard)
90
AnyTokens in
/
720
AnyTokens out
Limitations & Trade-offs
1
Responses API only. GPT-5 Pro is available exclusively through the Responses API, not Chat Completions. Teams with existing Chat Completions pipelines must adapt their integration, and any tooling that assumes the older interface will not work unchanged. If you need drop-in Chat Completions compatibility, standard GPT-5 is the better fit.
2
Minutes-long latency. Because GPT-5 Pro is designed to work through tough problems at high reasoning effort, OpenAI states some requests may take several minutes and recommends background mode to avoid timeouts. This rules out interactive, user-facing chat and any latency-sensitive workload. Route real-time traffic to a faster model and reserve GPT-5 Pro for asynchronous, high-value jobs.
3
Premium, high-effort cost profile. GPT-5 Pro carries substantially higher input and output token pricing than standard GPT-5, and because it only runs at high reasoning effort you cannot dial compute down to save money. Reasoning tokens count toward output billing, so long deliberations are expensive. For cost-sensitive or high-volume generation, a lower-effort model is more economical.
4
No code interpreter and fixed reasoning effort. GPT-5 Pro does not support the code interpreter, and reasoning effort is locked at high with no lower settings. Workflows that depend on sandboxed code execution inside the model, or that need to trade reasoning depth for speed and cost on a per-request basis, should use a model that exposes those controls.
Best-Fit Workloads
Where this model earns its place
01
Expert-Level Research and Analysis
GPT-5 Pro's extended reasoning targets exactly the problems where a careful, correct answer is worth the wait. Its state-of-the-art GPQA result reflects strength on graduate-level science reasoning, and OpenAI positions it for complex, economically valuable knowledge work across many professions. Use it for deep literature synthesis, technical due diligence, and analysis that would otherwise require a domain expert — running asynchronously so latency does not block users.
02
Hard Quantitative and Mathematical Problems
For difficult math and quantitative reasoning, GPT-5 Pro's high-effort deliberation raises the ceiling on correctness. The GPT-5 family posts strong AIME and math results, with GPT-5 Pro reaching a perfect AIME 2025 score when given a Python tool. This suits proof checking, advanced modeling, and quantitative research where a single high-quality answer justifies extended compute. Note that tool-assisted results depend on providing execution outside the model, since GPT-5 Pro lacks code interpreter.
03
Verification of High-Stakes Outputs
A cost-effective pattern is to generate with a faster, cheaper model and reserve GPT-5 Pro as a verification tier for the small fraction of outputs where errors are expensive — legal reasoning, safety-critical logic, or financial analysis. Its higher accuracy ceiling makes it a strong second-opinion or final-check model. Because requests run asynchronously, verification fits naturally into background pipelines rather than the interactive path.
04
Long-document reasoning over large context
The 400,000-token context window lets GPT-5 Pro reason over entire codebases, long specifications, or bundled technical documents in a single request, including image and PDF inputs. This suits deep contract analysis, cross-referencing large corpora, or reconciling multi-file logic. Watch output cost carefully: large contexts plus extended reasoning tokens make long-context Pro requests among the more expensive in the lineup.
Integration
01
One API integration
02
Easy model switching
03
Flexible for production
04