Model comparison
Gemini 3 Pro Deep Think vs GPT-5.3 Codex
Head-to-head evidence from 1 shared benchmark result across 1 category. Overall scores shown here use the public BenchAlign v5 ranking lane.
Public leaderboard positions: Gemini 3 Pro Deep Think #41 (Estimated); GPT-5.3 Codex #26 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.
Evidence parity. Gemini 3 Pro Deep Think and GPT-5.3 Codex share 1 comparable benchmark result. 0 of 8 categories are comparable. 1 result is unique to Gemini 3 Pro Deep Think; 20 to GPT-5.3 Codex.
Updated July 20, 2026- Shared results
- 1
- Gemini 3 Pro Deep Think only
- 1
- GPT-5.3 Codex only
- 20
- Comparable categories
- 0 / 8
Benchmark data for Gemini 3 Pro Deep Think and GPT-5.3 Codex is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 1 shared benchmark result across 1 evidence category; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
Gemini 3 Pro Deep Think has the larger context window at 2M, compared with 400K for GPT-5.3 Codex.
Category breakdown
Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.
| Category | Gemini 3 Pro Deep Think | Δ | GPT-5.3 Codex |
|---|---|---|---|
| Agentic | Gemini 3 Pro Deep ThinkNot measured | MarginNo overlap | GPT-5.3 Codex71.4 |
| Coding | Gemini 3 Pro Deep ThinkNot measured | MarginNo overlap | GPT-5.3 Codex67.2 |
| Reasoning | Gemini 3 Pro Deep Think45.1 | MarginNo overlap | GPT-5.3 CodexNot measured |
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Gemini 3 Pro Deep Think | GPT-5.3 Codex | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Gemini 3 Pro Deep ThinkNot available | GPT-5.3 Codex$1.75 input / $14 output | A complete price comparison is not available. |
| Generation speedtokens per second | Gemini 3 Pro Deep ThinkNot available | GPT-5.3 Codex79 tok/s | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Gemini 3 Pro Deep ThinkNot available | GPT-5.3 Codex88.26 s | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Gemini 3 Pro Deep Think2M | GPT-5.3 Codex400K | Gemini 3 Pro Deep Think lists the larger context window. |
Benchmark Deep Dive
Agentic5 benchmarks
Coding5 benchmarks
Reasoning3 benchmarks
Knowledge6 benchmarks
| Benchmark | Gemini 3 Pro Deep Think | GPT-5.3 Codex | Result |
|---|---|---|---|
| Artificial Analysis Intelligence IndexSource | — | 44.3% | Not comparable |
| AA-GPQA DiamondSource | — | 91.5% | Not comparable |
| AA-HLESource | — | 39.9% | Not comparable |
| AA-Omniscience IndexSource | — | 9.9% | Not comparable |
| AA-Omniscience AccuracySource | — | 51.8% | Not comparable |
| AA-Omniscience Hallucination RateSource | — | 86.9% | Not comparable |
Multimodal2 benchmarks
Inst. Following1 benchmarks
| Benchmark | Gemini 3 Pro Deep Think | GPT-5.3 Codex | Result |
|---|---|---|---|
| AA-IFBenchSource | — | 75.4% | Not comparable |
Frequently Asked Questions (3)
Can I compare Gemini 3 Pro Deep Think and GPT-5.3 Codex on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
What data is available for Gemini 3 Pro Deep Think and GPT-5.3 Codex today?
Gemini 3 Pro Deep Think: Pricing unavailable GPT-5.3 Codex: $1.75 input / $14.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.
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