Head-to-head
Gemini 3 Pro vs Claude Opus 4.6: which AI model wins in 2026?
Gemini 3 Pro ($12/1M out (prompts ≤200K)) and Claude Opus 4.6 ($25/1M out) are two of the most-used AI models in 2026. Across 3 community votes, Gemini 3 Pro leads with 57% approval.
Quick verdict
On Reasoning, pick Gemini 3 Pro: the arena rates it 4.5/5 against 4/5 for Claude Opus 4.6. On budget, Gemini 3 Pro wins: it starts at $12/1M out (prompts ≤200K) versus $25/1M out for Claude Opus 4.6.
Line-by-line comparison
Strengths and weaknesses
Gemini 3 Pro
- Topped LMArena at launch with a record 1501 Elo and scored 91.9% on GPQA Diamond, state of the art at release
- ARC-AGI-2 at 31.1%, roughly 6x Gemini 2.5 Pro (4.9%) and nearly double GPT-5.1 (17.6%) at the time
- Best-in-class multimodal understanding: 81% MMMU-Pro, 87.6% Video-MMMU, with a 1M-token context window
- Strong agentic coding: 76.2% SWE-bench Verified, 54.2% Terminal-Bench 2.0, 1487 Elo on WebDev Arena
- Undercut rivals on price at $2/$12 per 1M tokens, below Claude Sonnet-class pricing ($3/$15)
- Configurable thinking_level (low/medium/high) lets developers trade reasoning depth against latency and cost
- Overconfident hallucinations: on AA-Omniscience it gave a wrong answer 88% of the time instead of declining, vs 48% for Claude Sonnet 4.5 (the-decoder)
- Sycophancy widely reported by reviewers (Zvi Mowshowitz: 'vast intelligence with no spine'); needs tight system prompts
- Tool-calling reliability issues in agent stacks: devs reported tool outputs dumped into the chat thread and more scaffolding needed than OpenAI/Anthropic models
- Slow at high thinking level: time to first token measured around 30-60s on AI Studio despite ~130 tok/s output speed
- Retired: shut down on the Gemini API and AI Studio on March 9, 2026, with gemini-3-pro-preview now aliased to Gemini 3.1 Pro
Claude Opus 4.6
- 80.8% SWE-bench Verified (25-trial average) and top Terminal-Bench 2.0 score at launch, the leading agentic coding model of its generation (Feb 2026)
- First Opus with a 1M-token context window: 76% on MRCR v2 8-needle at 1M tokens vs 18.5% for Sonnet 4.5
- Large reasoning jump over Opus 4.5: ARC-AGI-2 68.8% vs 37.6%, +190 Elo on GDPval-AA economic-value tasks (~144 Elo over GPT-5.2)
- Kept Opus 4.5 pricing ($5/$25 per 1M tokens) despite the gains; full 1M context now billed at standard rates, 50% batch discount
- Adaptive thinking plus effort parameter (low/medium/high/max) to trade intelligence, latency and cost per request
- Strong autonomous agent behavior: parallelizes work and needs less handholding than Opus 4.5 (Every.to Vibe Check)
- Slower and more verbose than Opus 4.5; reviewers report the pace 'wavers under load' on long agentic runs (Every.to)
- Writing regressed: in blind tests Every.to's team preferred Opus 4.5's prose, and 4.6 shows more AI-isms like 'X not Y' constructions
- Sometimes makes unexpected changes and 'doesn't always know its own skills', requiring closer supervision than GPT-5.x Codex per reviewers
- Superseded within months by Opus 4.7 and 4.8 at the same $5/$25 price, and fast mode is not available on 4.6 since June 2026 (requests run at standard speed)
- Some devs report benchmark fatigue: day-to-day coding gains over 4.5 are harder to feel than the scores suggest, and SWE-bench itself was flat vs 4.5 (80.8% vs 80.9%)
Cast your verdict
One recommendation per tool per gladiator. It reshapes the crowd score everyone sees.
The arena’s verdict on Gemini 3 Pro
A landmark release that put Google back on top in late 2025, with a huge reasoning jump over Gemini 2.5 Pro and the best multimodal scores of its generation. As of mid-2026 there is no reason to choose it: Google shut it down on the API on March 9, 2026, and Gemini 3.1 Pro costs exactly the same while more than doubling ARC-AGI-2 performance (77.1% vs 31.1%). Teams on legacy deployments should migrate to 3.1 Pro, which the old model ID now points to anyway. Avoid it for hallucination-sensitive workloads unless you add grounding, a weakness reviewers flagged repeatedly.
The arena’s verdict on Claude Opus 4.6
A clear upgrade over Opus 4.5 for agentic coding and long-context work at identical pricing, and it held the top agentic coding benchmarks at launch. In mid-2026 however there is little reason to start new projects on it: Opus 4.8 costs the same $5/$25 and outperforms it across the board, so pick 4.6 mainly to pin an already-validated behavior. Writers should avoid it, since blind tests preferred Opus 4.5's prose, and latency-sensitive users should note it is slower than 4.5 with no fast mode option.
What the crowd says
On Gemini 3 Pro
“Confidently wrong is its worst mode. On AA-Omniscience it gave a wrong answer 88% of the time instead of declining. Add the sycophancy and you need a tight system prompt to trust it.”
“ARC-AGI-2 at 31% was about 6x Gemini 2.5 Pro and nearly double GPT-5.1 at the time. For visual-heavy work (81 MMMU-Pro) nothing else came close.”
“1501 Elo on LMArena at launch was deserved. Multimodal is where it kills, I feed it lecture videos and dense PDFs and it just gets it. 1M context helps.”
On Claude Opus 4.6
No verdicts yet. Be the first to speak.
Keep comparing
Frequently asked questions
Is Gemini 3 Pro better than Claude Opus 4.6?
The crowd currently sides with Gemini 3 Pro: 57% recommend it, versus 50% for Claude Opus 4.6 (3 votes). On Reasoning, Gemini 3 Pro rates higher (4.5/5 vs 4/5). The right pick depends on your use case. The line-by-line comparison on this page breaks down pricing, key specs and arena ratings.
Which is cheaper, Gemini 3 Pro or Claude Opus 4.6?
Gemini 3 Pro is cheaper: it starts at $12/1M out (prompts ≤200K), while Claude Opus 4.6 starts at $25/1M out.
How much do Gemini 3 Pro and Claude Opus 4.6 cost per 1M tokens?
Gemini 3 Pro: $2/1M in (prompts ≤200K) per 1M input tokens, $12/1M out (prompts ≤200K) per 1M output tokens. Claude Opus 4.6: $5/1M in per 1M input tokens, $25/1M out per 1M output tokens.