Anthropic Claude Opus 4.8 vsOpenAI o3 (Reasoning Model)
Compare the listed model data for Anthropic Claude Opus 4.8 by Anthropic and OpenAI o3 (Reasoning Model) by OpenAI. Benchmark and pricing records are not a controlled test and may change.
Data last updated: 2026-10-16. Verify current model details with each provider.
What the listed data says
Anthropic Claude Opus 4.8: 200K tokens; OpenAI o3 (Reasoning Model): 128K tokens. Anthropic Claude Opus 4.8 has the larger listed context window. Anthropic Claude Opus 4.8 is listed for coding, reasoning, vision, multimodal input, agentic workflows, long-context tasks; OpenAI o3 (Reasoning Model) is listed for coding, reasoning, vision, multimodal input, agentic workflows, long-context tasks. Shared catalog benchmark entries: HumanEval: Anthropic Claude Opus 4.8 90.5%; OpenAI o3 (Reasoning Model) 99.2%; SWE-bench Verified: Anthropic Claude Opus 4.8 62.3%; OpenAI o3 (Reasoning Model) 71.7%. These records are reference data, not a controlled head-to-head test; verify current pricing and specifications with each provider.
Catalog source links
Use these model and provider links to verify current specifications, pricing, and availability.
The listed context windows are 200K tokens and 128K tokens; the larger is 1.56× the smaller.
On shared numeric benchmark entries, HumanEval: Anthropic Claude Opus 4.8 − OpenAI o3 (Reasoning Model) = -8.7 percentage points (90.5% vs 99.2%); SWE-bench Verified: Anthropic Claude Opus 4.8 − OpenAI o3 (Reasoning Model) = -9.4 percentage points (62.3% vs 71.7%).
The first listed parameter quantities are ~200B+ (frontier MoE, exact size proprietary) and ~200B+ (frontier reasoning, exact size proprietary); the larger quantity is 1× the smaller. Total and active MoE parameters are not directly equivalent.
A release-date gap cannot be calculated from the catalog values (Anthropic Claude Opus 4.8: 2026; OpenAI o3 (Reasoning Model): 2025).
Cost example: 1M input and 1M output tokens
A cost example for 1M input plus 1M output tokens cannot be calculated reliably because separate numeric input and output rates are not listed for both models.
Choose Anthropic Claude Opus 4.8 if…
Choose Anthropic Claude Opus 4.8 when your task aligns with catalog-listed uses or strengths such as Complex enterprise analysis requiring maximum accuracy: financial modeling, legal review, scientific research, Long-document processing: contracts, research papers, technical specifications up to 200K tokens, Agentic software engineering: autonomous multi-file codebase changes and complex debugging, Graduate-level academic and scientific reasoning requiring deep domain knowledge.
Choose OpenAI o3 (Reasoning Model) if…
Choose OpenAI o3 (Reasoning Model) when your task aligns with catalog-listed uses or strengths such as Competition and graduate-level mathematics (AIME, Olympiad problems), Advanced scientific research: physics, chemistry, biology problem solving, Complex software engineering requiring full architectural reasoning, PhD-level research questions in STEM fields.
Anthropic's most powerful model ever. Deeper reasoning, stronger agentic coding, superior design sense, and sharper analytical precision than Opus 4.7.
Access via LITHOVEX AI free. Anthropic API: high-tier pricing.
Via LITHOVEX AI free. OpenAI API: premium pricing.
Listed input/output cost per 1M tokens
input $6, output $30 per 1M tokens
Separate numeric input/output rates not listed
License
Proprietary
Proprietary
Coding support
Listed
Listed
Reasoning support
Listed
Listed
Vision input
Listed
Listed
Multimodal
Listed
Listed
Open weights
No
No
Benchmark: HumanEval
90.5%
99.2%
Benchmark: SWE-bench Verified
62.3%
71.7%
Figures are transcribed from LITHOVEX model records. Benchmark versions and evaluation setups may differ; pricing and specifications can change. Check each provider's current documentation before making a decision.
Frequently Asked Questions
What is different between Anthropic Claude Opus 4.8 and OpenAI o3 (Reasoning Model)?
Anthropic Claude Opus 4.8: 200K tokens; OpenAI o3 (Reasoning Model): 128K tokens. Anthropic Claude Opus 4.8 has the larger listed context window. Anthropic Claude Opus 4.8 is listed for coding, reasoning, vision, multimodal input, agentic workflows, long-context tasks; OpenAI o3 (Reasoning Model) is listed for coding, reasoning, vision, multimodal input, agentic workflows, long-context tasks. Shared catalog benchmark entries: HumanEval: Anthropic Claude Opus 4.8 90.5%; OpenAI o3 (Reasoning Model) 99.2%; SWE-bench Verified: Anthropic Claude Opus 4.8 62.3%; OpenAI o3 (Reasoning Model) 71.7%. These records are reference data, not a controlled head-to-head test; verify current pricing and specifications with each provider.
What benchmark values are listed for Anthropic Claude Opus 4.8 and OpenAI o3 (Reasoning Model)?
HumanEval: Anthropic Claude Opus 4.8 90.5%; OpenAI o3 (Reasoning Model) 99.2%; SWE-bench Verified: Anthropic Claude Opus 4.8 62.3%; OpenAI o3 (Reasoning Model) 71.7%. The catalog values may use different versions and evaluation setups, so they are reference points rather than a controlled head-to-head result.
Which model has the larger listed context window?
Anthropic Claude Opus 4.8: 200K tokens; OpenAI o3 (Reasoning Model): 128K tokens. Anthropic Claude Opus 4.8 has the larger listed context window.
What are the listed costs per million tokens for Anthropic Claude Opus 4.8 and OpenAI o3 (Reasoning Model)?
Anthropic Claude Opus 4.8: input $6, output $30 per 1M tokens (Access via LITHOVEX AI free. Anthropic API: high-tier pricing.). OpenAI o3 (Reasoning Model): Separate numeric input/output rates not listed (Via LITHOVEX AI free. OpenAI API: premium pricing.). Where separate numeric input and output rates are available, the worked example uses 1M input plus 1M output tokens. Confirm current terms with each provider.
How far apart are the listed release dates for Anthropic Claude Opus 4.8 and OpenAI o3 (Reasoning Model)?
The catalog lists Anthropic Claude Opus 4.8 as 2026 and OpenAI o3 (Reasoning Model) as 2025; a release-date gap cannot be calculated from both records.
When was the comparison data last updated?
The model catalog records 2026-10-16 as its data update date. Provider specifications and prices may have changed since then.
How should I choose between Anthropic Claude Opus 4.8 and OpenAI o3 (Reasoning Model)?
Compare the listed specifications and capabilities, review the benchmark notes, then test both with the same representative prompt for your task. This page does not claim a universal winner.
Create your free LITHOVEX account and compare Anthropic Claude Opus 4.8 and OpenAI o3 (Reasoning Model) on your actual tasks. No credit card, no API key, no subscriptions needed.