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TokenMath.net
Updated 2026-09-22 11:16 UTC
Head-to-Head Specification Battle

OpenAI o4-mini vs DeepSeek-V3 (Legacy API Alias)

Side-by-side technical and economic comparison between OpenAI's OpenAI o4-mini and DeepSeek's DeepSeek-V3 (Legacy API Alias).

Endpoint Availability & Transition Notice

DeepSeek-V3 (Legacy API Alias): Classified as a Legacy Reference model (Legacy Reference (API Aliased)).

Core Technical & Pricing Comparison
MetricOpenAI o4-miniDeepSeek-V3 (Legacy API Alias)Advantage
Provider OrganizationOpenAIDeepSeek
Standard Input / 1M$1.10$0.14DeepSeek-V3 (Legacy API Alias) (87% lower)
Cached Input / 1M$0.275$0.014DeepSeek-V3 (Legacy API Alias) lower
Output / 1M$4.40$0.28DeepSeek-V3 (Legacy API Alias) lower
Context Window200k128kOpenAI o4-mini (200k)
Max Generation Tokens64k8.2kOpenAI o4-mini
Tokenizer FamilyOpenAI o200k_base (200k vocabulary)DeepSeek Byte-level BPE (~128k vocabulary)

Interactive Side-by-Side Cost Simulator

Live Delta
Input Tokens / Req2,500
Output Tokens / Req800
Daily Requests10,000
OpenAI o4-mini
$1,571.63 / month
$0.00524 / request
DeepSeek-V3 (Legacy API Alias)LOWER COST
$124.95 / month
$0.00042 / request
Selecting DeepSeek-V3 (Legacy API Alias) saves $1,446.68 / month (92.0% savings) over OpenAI o4-mini.

When to Choose OpenAI o4-mini

Opt for OpenAI o4-mini 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 $1.1/M input rate.

When to Choose DeepSeek-V3 (Legacy API Alias)

Opt for DeepSeek-V3 (Legacy API Alias) when looking for DeepSeek's tooling integration, specific context window depth (128k tokens), or when output generation volume favors its $0.28/M rate.