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Gemini 3 Flash vs GPT-5.3 Codex
Comprehensive side-by-side LLM comparison
Both models show comparable benchmark performance. Gemini 3 Flash supports multimodal inputs. Gemini 3 Flash is available on 2 providers. Both models have their strengths depending on your specific coding needs.
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Google DeepMind
Gemini 3 Flash, released by Google in December 2025, is a large language model from the Gemini 3 family that delivers reasoning and coding performance with efficiency optimized for high-volume workloads. It features a 1M token context window, 64K maximum output tokens, and native support for text, image, audio, video, and PDF input. Gemini 3 Flash targets cost-sensitive agentic workflows, document processing, and production APIs requiring fast, capable multimodal responses.
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OpenAI
GPT-5.3 Codex, released by OpenAI in February 2026, is a coding-specialized large language model from the GPT-5.3 family. It targets software engineering workflows including automated code generation, test writing, and agentic multi-file editing, built on the incremental improvements of the GPT-5.3 generation.
1 month newer
Gemini 3 Flash
Google DeepMind
2025-12-17
GPT-5.3 Codex
OpenAI
2026-02
Performance Metrics
Context window and performance specifications
Average performance across 1 common benchmarks
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Gemini 3 Flash
Average Score:64.3%
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GPT-5.3 Codex
Average Score:64.7%(+0.4%)
Performance comparison across key benchmark categories
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Gemini 3 Flash
Coding64.3%
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GPT-5.3 Codex
Coding64.7%(+0.4%)
Provider Availability & Performance
Available providers and their performance metrics
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Gemini 3 Flash
2 providers
Google Cloud Vertex AI
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GPT-5.3 Codex
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Gemini 3 Flash
Avg Score:64.3%
Providers:2
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GPT-5.3 Codex
Avg Score:64.7%(+0.4%)
Providers:0