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GPT-5.3-Codex vs GPT-5.6 Sol

GPT-5.3-Codex

OpenAI

88#23
vs
GPT-5.6 Sol

OpenAI

89#21
Signal-by-Signal Comparison
SignalGPT-5.3-CodexDeltaGPT-5.6 Sol
Capabilities
100
--
100
Benchmarks
88
--
88
Pricing
86
+16
70
Context window size
80
-6
86
Recency
100
--
100
Output Capacity
85
--
85
Overall Result
1 wins
of 6
1 wins
It's a tie - both models win 1 signals each

Score History

Score History (21 data points)
GPT-5.3-CodexGPT-5.6 Sol
GPT-5.3-Codex

88.2

current score

Leader

GPT-5.6 Sol

right now

GPT-5.6 Sol

88.5

current score

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

GPT-5.3-Codex

OpenAI

Best Value
Per request$0.008750
Daily$29.17
Monthly$875.00
Annual$10500.00

GPT-5.6 Sol

OpenAI

Per request$0.020000
Daily$66.67
Monthly$2000.00
Annual$24000.00

GPT-5.3-Codex saves you $1125.00/month

That's $13500.00/year compared to GPT-5.6 Sol at your current usage level of 100K calls/month.

56% cheaper
Choose GPT-5.3-Codex for cost optimization

GPT-5.3-Codex pricing:
Input:$1.75/M tokens
Output:$14.00/M tokens
GPT-5.6 Sol pricing:
Input:$5.00/M tokens
Output:$30.00/M tokens
GPT-5.3-Codex

OpenAI

88

Composite Score

Winner
GPT-5.6 Sol

OpenAI

89

Composite Score

Signal-by-Signal Comparison
MetricGPT-5.3-CodexGPT-5.6 SolWinner
Overall Score
88
89
GPT-5.6 Sol
Rank#23#21
GPT-5.6 Sol
Quality Rank#23#21
GPT-5.6 Sol
Adoption Rank#23#21
GPT-5.6 Sol
Parameters------
Context Window400K1050K
GPT-5.6 Sol
Pricing$1.75/$14.00/M$5.00/$30.00/M--
Signal Scores
Capabilities
100
100
GPT-5.3-Codex
Benchmarks
88
88
GPT-5.3-Codex
Pricing
86
70
GPT-5.3-Codex
Context window size
80
86
GPT-5.6 Sol
Recency
100
100
GPT-5.3-Codex
Output Capacity
85
85
GPT-5.3-Codex
Benchmark Head-to-Head(11 benchmarks)
GPT-5.3-Codex: 011 tiesGPT-5.6 Sol: 0
GPT-5.3-Codex
GPT-5.6 Sol
Normalized 0-100%
MMLU
93%93%
MMLU-Pro
84.5%84.5%
GPQA Diamond
85%85%
MATH-500
92.5%92.5%
HumanEval
96.5%96.5%
SWE-bench Verified
75%75%
IFEval
92%92%
BBH
90.5%90.5%
Arena Elo
14651465
LiveBench
76%76%
HLE
35%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-5.3-CodexElite Tier

Scores 88/100 (rank #23), placing it in the top 92% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100
GPT-5.6 SolElite Tier

Scores 89/100 (rank #21), placing it in the top 93% 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-5.3-Codex when you need:

  • High-volume production workloads where API costs must be minimized
  • Step-by-step reasoning and chain-of-thought problem solving

Choose GPT-5.6 Sol when you need:

  • Processing long documents or large codebases (1050K token context)
  • Step-by-step reasoning and chain-of-thought problem solving
Cost-Performance Analysis
GPT-5.3-CodexBest Value
Input cost$1.75/M tokens
Output cost$14.00/M tokens
Cost per quality point$0.179
Est. monthly (1M tokens/day)$236.25
GPT-5.6 Sol
Input cost$5.00/M tokens
Output cost$30.00/M tokens
Cost per quality point$0.395
Est. monthly (1M tokens/day)$525.00

GPT-5.3-Codex offers 55% better value per quality point. At 1M tokens/day, you'd spend $236.25/month with GPT-5.3-Codex vs $525.00/month with GPT-5.6 Sol - a $288.75 monthly difference.

Latency & Speed
GPT-5.3-CodexFaster
Speed score0/100
GPT-5.6 Sol
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-5.3-Codex

Customer support chatbot

Suitable for user-facing chat with competitive response times. GPT-5.3-Codex also offers lower per-token costs for high-volume support

GPT-5.3-Codex

Long document analysis

Larger context window (1050K tokens) can process longer documents, contracts, and research papers in a single pass

GPT-5.6 Sol

Batch data extraction

Lower output pricing ($14.00/M) reduces costs when processing thousands of records daily

GPT-5.3-Codex

Creative writing & content

Higher overall composite score (89/100) correlates with better nuance, coherence, and style in long-form content

GPT-5.6 Sol

Image understanding & OCR

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

GPT-5.3-Codex
Which Should You Choose?
Our recommendation:
GPT-5.6 Sol

GPT-5.3-Codex and GPT-5.6 Sol are extremely close in overall performance (only 0.29999999999999716 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.

by OpenAI

  • Choose for Quality - Marginally better benchmark scores; both are excellent
  • Choose for Cost - 55% 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
GPT-5.6 Sol
Recommended

by OpenAI

Consider for specialized use cases.

Capability Comparison
CapabilityGPT-5.3-CodexGPT-5.6 Sol
Vision (Image Input)
Function Calling
Streaming
JSON Mode
Reasoning
Web Search
Image Output
Monthly Cost Calculator
1,000tokens (600 in / 400 out)
100requests/day (3,000/month)

GPT-5.3-Codex

OpenAI

Best Value
$19.95
estimated monthly cost

GPT-5.6 Sol

OpenAI

$45.00
estimated monthly cost

GPT-5.3-Codex saves you $25.05/month

That's 56% cheaper than GPT-5.6 Sol at 1,000 tokens/request and 100 requests/day.

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

Parameters & Context
ParameterGPT-5.3-CodexGPT-5.6 Sol
Context Window400K1.1M
Max Output Tokens128,000128,000
Open SourceNoNo
CreatedFeb 24, 2026Jul 9, 2026
Last updated: 14m ago

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GPT-5.3-Codex vs GPT-5.6 Sol (2026) | LM Market Cap