{T}
TokenMath.net
Updated 2026-09-15 14:30 UTC
Head-to-Head Specification Battle

OpenAI o1 vs Claude Opus 5

Side-by-side technical and economic comparison between OpenAI's OpenAI o1 and Anthropic's Claude Opus 5.

Core Technical & Pricing Comparison
MetricOpenAI o1Claude Opus 5Advantage
Provider OrganizationOpenAIAnthropic
Standard Input / 1M$15.00$5.00Claude Opus 5 (67% lower)
Cached Input / 1M$7.50$0.50Claude Opus 5 lower
Output / 1M$60.00$25.00Claude Opus 5 lower
Context Window200k1MClaude Opus 5 (1M)
Max Generation Tokens100k16.4kOpenAI o1
Tokenizer FamilyOpenAI o200k_base (200k vocabulary)Anthropic Claude BPE (~65k vocabulary)

Interactive Side-by-Side Cost Simulator

Live Delta
Input Tokens / Req2,500
Output Tokens / Req800
Daily Requests10,000
OpenAI o1
$22,837.50 / month
$0.0761 / request
Claude Opus 5LOWER COST
$8,062.50 / month
$0.0269 / request
Selecting Claude Opus 5 saves $14,775.00 / month (64.7% savings) over OpenAI o1.

When to Choose OpenAI o1

Opt for OpenAI o1 when your engineering requirements prioritize OpenAI's ecosystem, specific tokenizer efficiencies (Exact BPE (o200k_base)), or when your expected prompt-to-completion ratios favor its $15/M input rate.

When to Choose Claude Opus 5

Opt for Claude Opus 5 when looking for Anthropic's tooling integration, specific context window depth (1M tokens), or when output generation volume favors its $25/M rate.