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GPT-5 Chat vs GPT-5 Codex

GPT-5 Chat

OpenAI

88#34
vs
GPT-5 Codex

OpenAI

88#33
Signal-by-Signal Comparison
SignalGPT-5 ChatDeltaGPT-5 Codex
Capabilities
67
-33
100
Benchmarks
70
-17
88
Pricing
90
--
90
Context window size
73
-7
80
Recency
71
-8
80
Output Capacity
70
-15
85
Overall Result
0 wins
of 6
5 wins
GPT-5 Codex wins 5 of 6 signals

Score History

Score History (21 data points)
GPT-5 ChatGPT-5 Codex
GPT-5 Chat

88.2

current score

Leader

Tied

right now

GPT-5 Codex

88.2

current score

LMMarketCap.com
Interactive Price Comparison
100Kcalls/month
1,000tokens (~1,333 chars)
500tokens (~667 chars)

GPT-5 Chat

OpenAI

Per request$0.006250
Daily$20.83
Monthly$625.00
Annual$7500.00

GPT-5 Codex

OpenAI

Per request$0.006250
Daily$20.83
Monthly$625.00
Annual$7500.00
GPT-5 Chat pricing:
Input:$1.25/M tokens
Output:$10.00/M tokens
GPT-5 Codex pricing:
Input:$1.25/M tokens
Output:$10.00/M tokens
Tie
GPT-5 Chat

OpenAI

88

Composite Score

Tie
GPT-5 Codex

OpenAI

88

Composite Score

Signal-by-Signal Comparison
MetricGPT-5 ChatGPT-5 CodexWinner
Overall Score
88
88
--
Rank#34#33
GPT-5 Codex
Quality Rank#34#33
GPT-5 Codex
Adoption Rank#34#33
GPT-5 Codex
Parameters------
Context Window128K400K
GPT-5 Codex
Pricing$1.25/$10.00/M$1.25/$10.00/M--
Signal Scores
Capabilities
67
100
GPT-5 Codex
Benchmarks
70
88
GPT-5 Codex
Pricing
90
90
GPT-5 Chat
Context window size
73
80
GPT-5 Codex
Recency
71
80
GPT-5 Codex
Output Capacity
70
85
GPT-5 Codex
Benchmark Head-to-Head(11 benchmarks)
GPT-5 Chat: 0GPT-5 Codex: 1
GPT-5 Chat
GPT-5 Codex
Normalized 0-100%
MMLU
-93%
MMLU-Pro
-84.5%
GPQA Diamond
-85%
MATH-500
-92.5%
HumanEval
-96.5%
SWE-bench Verified
-75%
IFEval
-92%
BBH
-90.5%
Arena Elo
14271465
LiveBench
-76%
HLE
-35%
Benchmark Interpretation

Our score (0-100) is driven by benchmark performance (90%) from Arena Elo ratings, MMLU, GPQA, HumanEval, SWE-bench, and 15+ standardized evaluations. Capabilities and context window serve as tiebreakers (10%). Learn more about our methodology.

GPT-5 ChatElite Tier

Scores 88/100 (rank #34), placing it in the top 89% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100
GPT-5 CodexElite Tier

Scores 88/100 (rank #33), placing it in the top 89% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100

With only a 0-point gap, these models are in the same performance tier. The practical difference in output quality is minimal - your choice should depend on pricing, latency requirements, and specific feature needs.

When to Use Each Model

Choose GPT-5 Chat when you need:

  • General-purpose tasks across coding, writing, and analysis

Choose GPT-5 Codex when you need:

  • Processing long documents or large codebases (400K token context)
  • Agentic applications using tool/function calling
  • Step-by-step reasoning and chain-of-thought problem solving
Cost-Performance Analysis
GPT-5 ChatBest Value
Input cost$1.25/M tokens
Output cost$10.00/M tokens
Cost per quality point$0.128
Est. monthly (1M tokens/day)$168.75
GPT-5 Codex
Input cost$1.25/M tokens
Output cost$10.00/M tokens
Cost per quality point$0.128
Est. monthly (1M tokens/day)$168.75

Both models are priced similarly, so the decision comes down to quality and features rather than cost.

Latency & Speed
GPT-5 ChatFaster
Speed score0/100
GPT-5 Codex
Speed score0/100

Both models have comparable response speeds. For most applications, the latency difference is negligible.

When latency matters most: Interactive chatbots, IDE code completion, real-time translation, and user-facing applications where response time directly impacts experience. For batch processing, background summarization, or offline analysis, latency is less critical.

Example Use Cases

Code generation & review

Based on overall model capabilities and architecture for coding tasks like generating functions, debugging, and refactoring

GPT-5 Chat

Customer support chatbot

Suitable for user-facing chat with competitive response times. GPT-5 Chat also offers lower per-token costs for high-volume support

GPT-5 Chat

Long document analysis

Larger context window (400K tokens) can process longer documents, contracts, and research papers in a single pass

GPT-5 Codex

Batch data extraction

Lower output pricing ($10.00/M) reduces costs when processing thousands of records daily

GPT-5 Chat

Creative writing & content

Higher overall composite score (88/100) correlates with better nuance, coherence, and style in long-form content

GPT-5 Chat

Image understanding & OCR

Supports vision input - can analyze screenshots, diagrams, photos, and scanned documents directly

GPT-5 Chat
Which Should You Choose?
Our recommendation:
GPT-5 Chat

GPT-5 Chat and GPT-5 Codex are extremely close in overall performance (only 0 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.

GPT-5 Chat
Recommended

by OpenAI

  • Choose for Quality - Marginally better benchmark scores; both are excellent
  • Choose for Cost - 0% lower pricing; better value at scale
  • Choose for Reliability - Higher uptime and faster response speeds
  • Choose for Prototyping - Stronger community support and better developer experience
  • Choose for Production - Wider enterprise adoption and proven at scale

by OpenAI

Consider for specialized use cases.

Capability Comparison
CapabilityGPT-5 ChatGPT-5 Codex
Vision (Image Input)
Function Callingdiffers
Streaming
JSON Mode
Reasoningdiffers
Web Search
Image Output
Monthly Cost Calculator
1,000tokens (600 in / 400 out)
100requests/day (3,000/month)

GPT-5 Chat

OpenAI

$14.25
estimated monthly cost

GPT-5 Codex

OpenAI

$14.25
estimated monthly cost

Assumes 60% input / 40% output token ratio per request. Actual costs may vary based on your usage pattern.

Parameters & Context
ParameterGPT-5 ChatGPT-5 Codex
Context Window128K400K
Max Output Tokens16,384128,000
Open SourceNoNo
CreatedAug 7, 2025Sep 23, 2025
Last updated: 37m ago

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