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GPT-5.3 Chat vs o3 Pro

GPT-5.3 Chat

OpenAI

87#28
vs
o3 Pro

OpenAI

86#30
Signal-by-Signal Comparison
SignalGPT-5.3 ChatDeltao3 Pro
Capabilities
83
-17
100
Benchmarks
88
-1
88
Pricing
86
+66
20
Context window size
73
-3
76
Recency
100
+39
61
Output Capacity
70
-13
83
Overall Result
2 wins
of 6
4 wins
o3 Pro wins 4 of 6 signals

Score History

Score History (21 data points)
GPT-5.3 Chato3 Pro
GPT-5.3 Chat

87

current score

Leader

GPT-5.3 Chat

right now

o3 Pro

86.3

current score

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

GPT-5.3 Chat

OpenAI

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

o3 Pro

OpenAI

Per request$0.060000
Daily$200.00
Monthly$6000.00
Annual$72000.00

GPT-5.3 Chat saves you $5125.00/month

That's $61500.00/year compared to o3 Pro at your current usage level of 100K calls/month.

85% cheaper
Choose GPT-5.3 Chat for cost optimization

GPT-5.3 Chat pricing:
Input:$1.75/M tokens
Output:$14.00/M tokens
o3 Pro pricing:
Input:$20.00/M tokens
Output:$80.00/M tokens
Winner
GPT-5.3 Chat

OpenAI

87

Composite Score

o3 Pro

OpenAI

86

Composite Score

Signal-by-Signal Comparison
MetricGPT-5.3 Chato3 ProWinner
Overall Score
87
86
GPT-5.3 Chat
Rank#28#30
GPT-5.3 Chat
Quality Rank#28#30
GPT-5.3 Chat
Adoption Rank#28#30
GPT-5.3 Chat
Parameters------
Context Window128K200K
o3 Pro
Pricing$1.75/$14.00/M$20.00/$80.00/M--
Signal Scores
Capabilities
83
100
o3 Pro
Benchmarks
88
88
o3 Pro
Pricing
86
20
GPT-5.3 Chat
Context window size
73
76
o3 Pro
Recency
100
61
GPT-5.3 Chat
Output Capacity
70
83
o3 Pro
Benchmark Head-to-Head(12 benchmarks)
GPT-5.3 Chat: 51 tieso3 Pro: 5
GPT-5.3 Chat
o3 Pro
Normalized 0-100%
MMLU
93%92.3%
MMLU-Pro
84.5%85.8%
GPQA Diamond
85%87.7%
MATH-500
92.5%99%
HumanEval
96.5%97%
SWE-bench Verified
75%71.7%
AIME 2024
-96.7%
IFEval
92%92%
BBH
90.5%93%
Arena Elo
14651415
LiveBench
76%74.8%
HLE
35%30.1%
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 ChatElite Tier

Scores 87/100 (rank #28), placing it in the top 91% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100
o3 ProElite Tier

Scores 86/100 (rank #30), placing it in the top 90% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100

With only a 1-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 Chat when you need:

  • High-volume production workloads where API costs must be minimized

Choose o3 Pro when you need:

  • Processing long documents or large codebases (200K token context)
  • Step-by-step reasoning and chain-of-thought problem solving
Cost-Performance Analysis
GPT-5.3 ChatBest Value
Input cost$1.75/M tokens
Output cost$14.00/M tokens
Cost per quality point$0.181
Est. monthly (1M tokens/day)$236.25
o3 Pro
Input cost$20.00/M tokens
Output cost$80.00/M tokens
Cost per quality point$1.159
Est. monthly (1M tokens/day)$1500.00

GPT-5.3 Chat offers 84% better value per quality point. At 1M tokens/day, you'd spend $236.25/month with GPT-5.3 Chat vs $1500.00/month with o3 Pro - a $1263.75 monthly difference.

Latency & Speed
GPT-5.3 ChatFaster
Speed score0/100
o3 Pro
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 Chat

Customer support chatbot

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

GPT-5.3 Chat

Long document analysis

Larger context window (200K tokens) can process longer documents, contracts, and research papers in a single pass

o3 Pro

Batch data extraction

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

GPT-5.3 Chat

Creative writing & content

Higher overall composite score (87/100) correlates with better nuance, coherence, and style in long-form content

GPT-5.3 Chat

Image understanding & OCR

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

GPT-5.3 Chat
Which Should You Choose?
Our recommendation:
GPT-5.3 Chat

GPT-5.3 Chat and o3 Pro are extremely close in overall performance (only 0.7000000000000028 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.

GPT-5.3 Chat
Recommended

by OpenAI

  • Choose for Quality - Marginally better benchmark scores; both are excellent
  • Choose for Cost - 84% 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-5.3 Chato3 Pro
Vision (Image Input)
Function Calling
Streaming
JSON Mode
Reasoningdiffers
Web Search
Image Output
Monthly Cost Calculator
1,000tokens (600 in / 400 out)
100requests/day (3,000/month)

GPT-5.3 Chat

OpenAI

Best Value
$19.95
estimated monthly cost

o3 Pro

OpenAI

$132.00
estimated monthly cost

GPT-5.3 Chat saves you $112.05/month

That's 85% cheaper than o3 Pro 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 Chato3 Pro
Context Window128K200K
Max Output Tokens16,384100,000
Open SourceNoNo
CreatedMar 3, 2026Jun 10, 2025
Last updated: 5m ago

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