Version of o3 with more compute for better, more precise responses. Best for complex reasoning tasks where accuracy is paramount.
o3-pro is OpenAI's pre-GPT-5 reasoning specialist, released on June 10, 2025 as a higher-compute variant of the o3 reasoning model. It uses the same underlying weights as o3 but invests substantially more inference-time compute in each step, which OpenAI describes as 'thinking harder' to deliver consistently better, more precise answers. On TheRouter, openai/o3-pro is mapped to the standard chat completions endpoint at $20 per 1M input tokens and $80 per 1M output tokens, and exposes a 200K context window with up to 100K output tokens.
o3-pro replaced o1-pro in ChatGPT and is OpenAI's recommended model for problems where accuracy matters more than latency — expert evaluators preferred its answers over o3 in every tested category, especially science, education, programming, business, and writing help. The model has full tool access (web search, file analysis, vision, Python, memory) but cannot generate images, does not support Canvas, and individual responses can take several minutes. Once GPT-5 Pro shipped at DevDay 2025, o3-pro became the cost-effective alternative when teams need deep reasoning without paying GPT-5 Pro's $18.75/$150 per 1M tokens.
| Type | Rate |
|---|---|
| Input | $21.60 / 1M tokens |
| Output | $86.40 / 1M tokens |
| Release date | 2025-06-10techcrunch.com ↗ | verified |
| Knowledge cutoff | May 2024llm-stats.com ↗ | verified |
| Reasoning mode | High-compute reasoning by default; same underlying model as o3 with more inference-time computeplatform.openai.com ↗ | verified |
| Native API surface | Responses API only; TheRouter exposes via chat completions endpointplatform.openai.com ↗ | verified |
| Tool support | Web search, file analysis, vision, Python, memory; cannot generate images; Canvas not supportedtechcrunch.com ↗ | verified |
| License | OpenAI Terms of Use (proprietary, API-only) | verified |
| Benchmark | Distribution | Score | Source |
|---|---|---|---|
AIME 2024 OpenAI's launch comparison reported o3-pro ahead of Google's Gemini 2.5 Pro on the 2024 American Invitational Mathematics Examination. Reddit community summaries from launch day put the figure at ~93% (Gemini 2.5 Pro 0605 ~89% on the same chart). | 93%% | r/singularity launch-day benchmarks thread ↗ | |
GPQA Diamond PhD-level science Q&A. OpenAI's launch numbers showed o3-pro ahead of Anthropic's Claude 4 Opus on this benchmark, at ~84% (community summaries also reference Gemini 2.5 Pro 0605 at ~86% on the same plot). | 84%% | techcrunch.com ↗ | |
4-for-4 reliability (AIME 2024) OpenAI's 'reliability' metric requires the model to answer the same problem correctly four times in a row. o3-pro reaches 90% on AIME 2024 under this stricter measurement, illustrating that the extra inference compute reduces variance, not just average accuracy. | 90%% | OpenAI launch chart summary ↗ | |
4-for-4 reliability (GPQA Diamond) On the same 4-for-4 reliability test against GPQA Diamond, o3-pro answers correctly four consecutive times in 76% of attempts — substantially above what o3 achieves on the same harness. | 76%% | OpenAI launch chart summary ↗ |
Use the global api.therouter.ai endpoint shown below for new integrations; the legacy China accelerated endpoint is retired.
curl https://api.therouter.ai/v1/chat/completions -H "Content-Type: application/json" -H "Authorization: Bearer $THE_ROUTER_API_KEY" -d '{
"model": "openai/o3-pro",
"messages": [
{"role": "user", "content": "Summarize the key points from this input."}
]
}'Call openai/o3-pro through TheRouter's standard chat completions endpoint. The reasoning chain runs server-side and the model returns the final answer in a single message. Hard problems can take minutes — raise your client timeout to at least 600s.
curl https://api.therouter.ai/v1/chat/completions \
-H "Authorization: Bearer $THEROUTER_API_KEY" \
-H "Content-Type: application/json" \
--max-time 900 \
-d '{
"model": "openai/o3-pro",
"messages": [
{"role": "user", "content": "Prove that for every prime p > 2, p^2 - 1 is divisible by 24. Show every step."}
]
}'OpenAI shipped GPT-5 Pro as the next-generation deep-reasoning flagship at DevDay 2025, overtaking o3-pro at the top of the OpenAI bench. o3-pro remains available through the API and is not deprecated, but teams building new UIs should evaluate GPT-5 Pro for the best available reasoning quality.
OpenAI launched o3-pro to all API tiers on June 10, 2025. The model replaced o1-pro in ChatGPT for Pro and Team users and came with full tool access (web, files, vision, Python, memory) at $20/$80 per 1M tokens. Expert evaluators rated it higher than o3 in every tested category, particularly science, education, and business writing.
OpenAI launched the o-series reasoning models o3 and o4-mini, and previewed o3-pro for launch in “a few weeks” with full tool support, positioning it as the tier above o3 for the hardest problems.
GPT-5 Pro (October 2025) overtook o3-pro on OpenAI's reasoning benchmarks and is the current recommended flagship. o3-pro remains a very capable model and is priced much lower ($20/$80 versus $18.75/$150), making it a strong cost/quality trade-off for teams that don't need the absolute top tier.
Both share the same underlying model weights. o3-pro runs with substantially more inference-time compute per step — OpenAI calls this 'thinking harder'. The result is higher accuracy and lower variance on hard problems (measurable through OpenAI's 4-for-4 reliability metric), at the cost of longer per-request latency and the higher $20/$80 price point.
Natively, o3-pro is a Responses API-only model. TheRouter maps it to the standard chat completions endpoint, so you call it with the familiar /v1/chat/completions path using your existing OpenAI-compatible client. The API accepts images, tools, reasoning parameters, and role-style messages as usual.
OpenAI warns that 'some requests may take several minutes to finish.' Third-party data from LLM-Stats lists ~30 s for a typical short prompt, with ~25 chars/s throughput. On genuinely hard reasoning problems (multi-page code dumps, heavy math proofs, multi-document research), expect three to ten minutes. On TheRouter, set client timeouts to at least 600–900 s and consider splitting very large problems across multiple requests when latency is a concern.
No. o3-pro is text-only on output. It can read images as input (useful for reasoning about diagrams, charts, and code screenshots), but for image generation you should use openai/gpt-image-2 or openai/chatgpt-image-latest.
| source | URL | retrieved | |
|---|---|---|---|
| Release date | techcrunch.com ↗ | 2026-06-01 | verified |
| Knowledge cutoff | llm-stats.com ↗ | 2026-06-01 | verified |
| Reasoning mode | platform.openai.com ↗ | 2026-06-01 | verified |
| Native API surface | platform.openai.com ↗ | 2026-06-01 | verified |
| Tool support | techcrunch.com ↗ | 2026-06-01 | verified |
| License | — | — | verified |
| AIME 2024 | r/singularity launch-day benchmarks thread ↗ | 2026-06-01 | to verify |
| GPQA Diamond | techcrunch.com ↗ | 2026-06-01 | to verify |
| 4-for-4 reliability (AIME 2024) | OpenAI launch chart summary ↗ | 2026-06-01 | to verify |
| 4-for-4 reliability (GPQA Diamond) | OpenAI launch chart summary ↗ | 2026-06-01 | to verify |
| GPT-5 Pro launched at OpenAI DevDay 2025 | openai.com ↗ | 2026-06-01 | verified |
| o3-pro released, replacing o1-pro | techcrunch.com ↗ | 2026-06-01 | verified |
| o3 and o4-mini launched, o3-pro preview announced | openai.com ↗ | 2026-06-01 | verified |
| How long do o3-pro responses take? | platform.openai.com ↗ | 2026-06-01 | to verify |