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Gemini 3.1 Pro Preview Custom Tools vs GPT-5.3 Chat

Signal-by-Signal Comparison
SignalGemini 3.1 Pro Preview Custom ToolsDeltaGPT-5.3 Chat
Capabilities
100
+17
83
Benchmarks
92
+4
88
Pricing
88
+2
86
Context window size
86
+13
73
Recency
100
--
100
Output Capacity
80
+10
70
Overall Result
5 wins
of 6
0 wins
Gemini 3.1 Pro Preview Custom Tools wins 5 of 6 signals

Score History

Score History (22 data points)
Gemini 3.1 Pro Preview Custom ToolsGPT-5.3 Chat
Gemini 3.1 Pro Preview Custom Tools

91.3

current score

Leader

Gemini 3.1 Pro Preview Custom Tools

right now

GPT-5.3 Chat

90.1

current score

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

Gemini 3.1 Pro Preview Custom Tools

Google

Best Value
Per request$0.008000
Daily$26.67
Monthly$800.00
Annual$9600.00

GPT-5.3 Chat

OpenAI

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

Gemini 3.1 Pro Preview Custom Tools saves you $75.00/month

That's $900.00/year compared to GPT-5.3 Chat at your current usage level of 100K calls/month.

9% cheaper
Choose Gemini 3.1 Pro Preview Custom Tools for cost optimization

Gemini 3.1 Pro Preview Custom Tools pricing:
Input:$2.00/M tokens
Output:$12.00/M tokens
GPT-5.3 Chat pricing:
Input:$1.75/M tokens
Output:$14.00/M tokens
Winner
Gemini 3.1 Pro Preview Custom Tools

Google

91

Composite Score

GPT-5.3 Chat

OpenAI

90

Composite Score

Signal-by-Signal Comparison
MetricGemini 3.1 Pro Preview Custom ToolsGPT-5.3 ChatWinner
Overall Score
91
90
Gemini 3.1 Pro Preview Custom Tools
Rank#10#12
Gemini 3.1 Pro Preview Custom Tools
Quality Rank#10#12
Gemini 3.1 Pro Preview Custom Tools
Adoption Rank#10#12
Gemini 3.1 Pro Preview Custom Tools
Parameters------
Context Window1049K128K
Gemini 3.1 Pro Preview Custom Tools
Pricing$2.00/$12.00/M$1.75/$14.00/M--
Signal Scores
Capabilities
100
83
Gemini 3.1 Pro Preview Custom Tools
Benchmarks
92
88
Gemini 3.1 Pro Preview Custom Tools
Pricing
88
86
Gemini 3.1 Pro Preview Custom Tools
Context window size
86
73
Gemini 3.1 Pro Preview Custom Tools
Recency
100
100
Gemini 3.1 Pro Preview Custom Tools
Output Capacity
80
70
Gemini 3.1 Pro Preview Custom Tools
Benchmark Head-to-Head(11 benchmarks)
Gemini 3.1: 3GPT-5.3 Chat: 1
Gemini 3.1
GPT-5.3 Chat
Normalized 0-100%
MMLU
92.6%93%
MMLU-Pro
-84.5%
GPQA Diamond
94.3%85%
MATH-500
-92.5%
HumanEval
-96.5%
SWE-bench Verified
80.6%75%
IFEval
-92%
BBH
-90.5%
Arena Elo
14941465
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.

Gemini 3.1 Pro Preview Custom ToolsElite Tier

Scores 91/100 (rank #10), placing it in the top 97% of all 290 models tracked.

Raw Quality0/100
Cost Efficiency0/100
Speed0/100
GPT-5.3 ChatElite Tier

Scores 90/100 (rank #12), placing it in the top 96% 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 Gemini 3.1 Pro Preview Custom Tools when you need:

  • Processing long documents or large codebases (1049K token context)
  • Step-by-step reasoning and chain-of-thought problem solving

Choose GPT-5.3 Chat when you need:

  • General-purpose tasks across coding, writing, and analysis
Cost-Performance Analysis
Gemini 3.1 Pro Preview Custom ToolsBest Value
Input cost$2.00/M tokens
Output cost$12.00/M tokens
Cost per quality point$0.153
Est. monthly (1M tokens/day)$210.00
GPT-5.3 Chat
Input cost$1.75/M tokens
Output cost$14.00/M tokens
Cost per quality point$0.175
Est. monthly (1M tokens/day)$236.25

Gemini 3.1 Pro Preview Custom Tools offers 11% better value per quality point. At 1M tokens/day, you'd spend $210.00/month with Gemini 3.1 Pro Preview Custom Tools vs $236.25/month with GPT-5.3 Chat - a $26.25 monthly difference.

Latency & Speed
Gemini 3.1 Pro Preview Custom ToolsFaster
Speed score0/100
GPT-5.3 Chat
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

Gemini 3.1 Pro Preview Custom Tools

Customer support chatbot

Suitable for user-facing chat with competitive response times. Gemini 3.1 Pro Preview Custom Tools also offers lower per-token costs for high-volume support

Gemini 3.1 Pro Preview Custom Tools

Long document analysis

Larger context window (1049K tokens) can process longer documents, contracts, and research papers in a single pass

Gemini 3.1 Pro Preview Custom Tools

Batch data extraction

Lower output pricing ($12.00/M) reduces costs when processing thousands of records daily

Gemini 3.1 Pro Preview Custom Tools

Creative writing & content

Higher overall composite score (91/100) correlates with better nuance, coherence, and style in long-form content

Gemini 3.1 Pro Preview Custom Tools

Image understanding & OCR

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

Gemini 3.1 Pro Preview Custom Tools
Which Should You Choose?
Our recommendation:
Gemini 3.1 Pro Preview Custom Tools

Gemini 3.1 Pro Preview Custom Tools and GPT-5.3 Chat are extremely close in overall performance (only 1.2000000000000028 points apart). Your best choice depends entirely on which specific strengths matter most for your use case.

by Google

  • Choose for Quality - Marginally better benchmark scores; both are excellent
  • Choose for Cost - 11% 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
CapabilityGemini 3.1 Pro Preview Custom ToolsGPT-5.3 Chat
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)

Gemini 3.1 Pro Preview Custom Tools

Google

Best Value
$18.00
estimated monthly cost

GPT-5.3 Chat

OpenAI

$19.95
estimated monthly cost

Gemini 3.1 Pro Preview Custom Tools saves you $1.95/month

That's 10% cheaper than GPT-5.3 Chat 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
ParameterGemini 3.1 Pro Preview Custom ToolsGPT-5.3 Chat
Context Window1.0M128K
Max Output Tokens65,53616,384
Open SourceNoNo
CreatedFeb 25, 2026Mar 3, 2026
Last updated: 58m ago

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