← Back to Model Hub/SIDE-BY-SIDE REVIEW
SHARE THIS:

GPT-5.1-Codex vs GPT-4o-mini

Detailed technical comparison between GPT-5.1-Codex (OpenAI) and GPT-4o-mini (OpenAI). Review live API token pricing, context window capabilities, time-to-first-token latency, and verified benchmark scores side-by-side.

⚡ Executive Summary & Verdict

Comparison Snapshot

GPT-5.1-Codex: 6 WinsvsGPT-4o-mini: 0 Wins
Context Leader

GPT-5.1-Codex

400,000 tokens
Agentic Tool-Calling

Tie

Equal Capability
Lowest Latency (TTFT)

Tie

Equal Speed
Input Price Leader

GPT-4o-mini

$0.15 / MTok
OpenAIactive

GPT-5.1-Codex

GPT-5.1-Codex is a specialized version of GPT-5.1 optimized for software engineering and coding workflows. It is designed for both interactive development sessions and long, independent execution of complex engineering tasks....

View GPT-5.1-Codex Full Specs →
OpenAIactive

GPT-4o-mini

GPT-4o mini is OpenAI's newest model after [GPT-4 Omni](/models/openai/gpt-4o), supporting both text and image inputs with text outputs. As their most advanced small model, it is many multiples more affordable...

View GPT-4o-mini Full Specs →

Technical Specifications

🏆 = Superior Spec
SpecificationGPT-5.1-CodexGPT-4o-mini
ProviderOpenAIOpenAI
Context Window400,000 tokens🏆128,000 tokens
Agent SuitabilityN/A82/100
Time to First Token (TTFT)N/A150 ms
Deployment Modelmanaged apimanaged api
Production Stabilitystablestable
API AvailableYesYes
Released Date2025-11-132024-07-18

API Pricing Comparison

Input Price per Million Tokens

GPT-5.1-Codex

$1.25

GPT-4o-mini

$0.15

Output Price per Million Tokens

GPT-5.1-Codex

$10.00

GPT-4o-mini

$0.60

💡 Cost Ratio: GPT-4o-mini is 8.3x cheaper per input token than GPT-5.1-Codex.

Want to test both models live?

Run side-by-side prompt benchmarks in our dynamic multi-model Sandbox. Compare execution speeds, latency metrics, and compute actual costs in real-time.

Open Live Sandbox Playground →

Benchmark Performance Metrics

Standardized Scores (0–100%)

Scores show verified raw accuracy percentages across standardized AI evaluation suites. Higher bars indicate superior performance in that domain.

MMLUGeneral knowledge & multi-task understanding
92.8%vs82.0%+10.8% GPT-5.1-Codex
GPT-5.1-Codex 🏆
GPT-4o-mini
HumanEvalPython coding & logic synthesis
99.0%vs84.0%+15.0% GPT-5.1-Codex
GPT-5.1-Codex 🏆
GPT-4o-mini
MATHComplex mathematical problem solving
81.2%vs70.2%+11.0% GPT-5.1-Codex
GPT-5.1-Codex 🏆
GPT-4o-mini
GPQAGraduate-level expert reasoning
59.6%vs45.0%+14.6% GPT-5.1-Codex
GPT-5.1-Codex 🏆
GPT-4o-mini
HellaSwagCommonsense reasoning and inference
88.4%vs84.7%+3.7% GPT-5.1-Codex
GPT-5.1-Codex 🏆
GPT-4o-mini
MT-BenchMulti-turn conversation flow quality
9.4%vs8.6%+0.8% GPT-5.1-Codex
GPT-5.1-Codex 🏆
GPT-4o-mini

GPT-5.1-Codex Quirks & Gotchas

No developer gotchas reported.

GPT-4o-mini Quirks & Gotchas

  • ▸Ultra-low latency — best TTFT in the OpenAI lineup
  • ▸Tool calling limited to single-step — not suitable for complex agentic pipelines

Explore Other Popular Comparisons

SIDE-BY-SIDE REVIEW

GPT-5.1-Codex vs Nano Banana 2 (Gemini 3.1 Flash Image)

Compare context windows, live API token prices, and benchmark scores.

SIDE-BY-SIDE REVIEW

GPT-5.1-Codex vs GLM 4.7 Flash

Compare context windows, live API token prices, and benchmark scores.

SIDE-BY-SIDE REVIEW

GPT-5.1-Codex vs GLM 5.2

Compare context windows, live API token prices, and benchmark scores.

SIDE-BY-SIDE REVIEW

GPT-5.1-Codex vs Nemotron 3 Ultra

Compare context windows, live API token prices, and benchmark scores.

SIDE-BY-SIDE REVIEW

GPT-5.1-Codex vs GPT-5.2-Codex

Compare context windows, live API token prices, and benchmark scores.

SIDE-BY-SIDE REVIEW

GPT-5.1-Codex vs DeepSeek V3.1

Compare context windows, live API token prices, and benchmark scores.