Pick Claude Sonnet 5 for agentic workflows that plan, use tools, and run autonomously or multi-step coding, debugging, and tool use. Pick Gemini 3.1 Pro for largest mainstream production context (2m) or long video and document analysis. On a tight budget at scale, Gemini 3.1 Pro is the value pick.
Claude Sonnet 5 (Anthropic) and Gemini 3.1 Pro (Google) are two of the models people most often weigh against each other in 2026. Claude Sonnet 5 is anthropic's most agentic Sonnet, with near-Opus-4.8 performance at Sonnet prices; the default model on Free and Pro. Gemini 3.1 Pro is a 2M-token multimodal workhorse — huge breadth, but recall fades deep in the window. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences
Price: Gemini 3.1 Pro is about 1.5× cheaper on input ($2/$12 per 1M tokens vs $3/$15 per 1M tokens) — modest, but it adds up at steady volume.
Context window: Gemini 3.1 Pro holds 2× more — 2M (~3,000 pages) vs 1M (~1,500 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
Recency: Claude Sonnet 5 is the newer model by about 4 months (released June 30, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
Claude Sonnet 5
Gemini 3.1 Pro
Provider
Anthropic (US)
Google (US)
Released
June 30, 2026
February 19, 2026
Context window
1M (~1,500 pages)
2M (~3,000 pages)
Price (in/out)
$3/$15 per 1M tokens
$2/$12 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, image, audio, video, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
26.3%
Who wins what
Agentic workflows that plan, use tools, and run autonomously: Claude Sonnet 5 — A core design strength of Claude Sonnet 5.
Multi-step coding, debugging, and tool use: Claude Sonnet 5 — A core design strength of Claude Sonnet 5.
Everyday professional and knowledge work: Claude Sonnet 5 — A core design strength of Claude Sonnet 5.
Largest mainstream production context (2M): Gemini 3.1 Pro — A core design strength of Gemini 3.1 Pro.
Long video and document analysis: Gemini 3.1 Pro — A core design strength of Gemini 3.1 Pro.
Agentic reasoning (high ARC-AGI-2): Gemini 3.1 Pro — A core design strength of Gemini 3.1 Pro.
Lowest cost at scale: Gemini 3.1 Pro — At $2/$12 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Largest single-prompt input: Gemini 3.1 Pro — Its 2M window is about 2× larger, fitting roughly 3,000 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume: Gemini 3.1 Pro — At $2/$12 per 1M tokens it undercuts Claude Sonnet 5, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases: Gemini 3.1 Pro — Larger 2M window fits more in one prompt.
Anyone whose priority is agentic workflows that plan, use tools, and run autonomously: Claude Sonnet 5 — It is specifically built for that.
Anyone whose priority is largest mainstream production context (2m): Gemini 3.1 Pro — That is its strongest area.
Claude Sonnet 5: where it fits
Anthropic's most agentic Sonnet, with near-Opus-4.8 performance at Sonnet prices; the default model on Free and Pro. Released June 30, 2026 by Anthropic, it is built for agentic workflows that plan, use tools, and run autonomously, multi-step coding, debugging, and tool use, everyday professional and knowledge work, and long-document analysis and reasoning.
Its trade-offs are real: lower peak accuracy than Opus 4.8 on the hardest tasks, and an updated tokenizer that can use 1.0-1.35x more tokens for the same text. At $3 in / $15 out per million tokens, it sits in the mid price band.
Gemini 3.1 Pro: where it fits
A 2M-token multimodal workhorse — huge breadth, but recall fades deep in the window. Released February 19, 2026 by Google, it is built for largest mainstream production context (2M), long video and document analysis, agentic reasoning (high ARC-AGI-2), and multimodal understanding.
Its trade-offs: long-context recall drops sharply past 256K, and premium price per token. At $2 in / $12 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
Claude Sonnet 5 and Gemini 3.1 Pro overlap enough that the right pick depends on your specific job. Gemini 3.1 Pro costs less per token; Gemini 3.1 Pro holds the larger context; and each leads in its own area — Claude Sonnet 5 for agentic workflows that plan, use tools, and run autonomously, Gemini 3.1 Pro for largest mainstream production context (2m). Rather than crowning one, run the same hard task through both once and let the results decide.
Frequently asked questions
Is Claude Sonnet 5 or Gemini 3.1 Pro better for coding?
Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Claude Sonnet 5 leans toward agentic workflows that plan, use tools, and run autonomously while Gemini 3.1 Pro leans toward largest mainstream production context (2m), and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Claude Sonnet 5 or Gemini 3.1 Pro?
Gemini 3.1 Pro is cheaper — $3/$15 per 1M tokens vs $2/$12 per 1M tokens, roughly 1.5× apart on input.
Which has the bigger context window?
Gemini 3.1 Pro — 2M vs 1M, about 2× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both Claude Sonnet 5 and Gemini 3.1 Pro together?
Yes — a multi-model platform like LumiChats gives you Claude Sonnet 5, Gemini 3.1 Pro and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.
Which is newer, Claude Sonnet 5 or Gemini 3.1 Pro?
Claude Sonnet 5 — released June 30, 2026, about 4 months after Gemini 3.1 Pro.
Claude Sonnet 5 vs Gemini 3.1 Pro
Anthropic · US | Google · US · Updated June 2026
Quick verdict
Pick Claude Sonnet 5 for agentic workflows that plan, use tools, and run autonomously or multi-step coding, debugging, and tool use. Pick Gemini 3.1 Pro for largest mainstream production context (2m) or long video and document analysis. On a tight budget at scale, Gemini 3.1 Pro is the value pick.
Claude Sonnet 5 (Anthropic) and Gemini 3.1 Pro (Google) are two of the models people most often weigh against each other in 2026. Claude Sonnet 5 is anthropic's most agentic Sonnet, with near-Opus-4.8 performance at Sonnet prices; the default model on Free and Pro. Gemini 3.1 Pro is a 2M-token multimodal workhorse — huge breadth, but recall fades deep in the window. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences at a glance
▸Price: Gemini 3.1 Pro is about 1.5× cheaper on input ($2/$12 per 1M tokens vs $3/$15 per 1M tokens) — modest, but it adds up at steady volume.
▸Context window: Gemini 3.1 Pro holds 2× more — 2M (~3,000 pages) vs 1M (~1,500 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
▸Recency: Claude Sonnet 5 is the newer model by about 4 months (released June 30, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
Claude Sonnet 5
Gemini 3.1 Pro
Provider
Anthropic (US)
Google (US)
Released
June 30, 2026
February 19, 2026
Context window
1M (~1,500 pages)
2M (~3,000 pages)
Price (in/out)
$3/$15 per 1M tokens
$2/$12 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, image, audio, video, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
26.3%
Who wins what
Agentic workflows that plan, use tools, and run autonomously
Claude Sonnet 5
A core design strength of Claude Sonnet 5.
Multi-step coding, debugging, and tool use
Claude Sonnet 5
A core design strength of Claude Sonnet 5.
Everyday professional and knowledge work
Claude Sonnet 5
A core design strength of Claude Sonnet 5.
Largest mainstream production context (2M)
Gemini 3.1 Pro
A core design strength of Gemini 3.1 Pro.
Long video and document analysis
Gemini 3.1 Pro
A core design strength of Gemini 3.1 Pro.
Agentic reasoning (high ARC-AGI-2)
Gemini 3.1 Pro
A core design strength of Gemini 3.1 Pro.
Lowest cost at scale
Gemini 3.1 Pro
At $2/$12 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Largest single-prompt input
Gemini 3.1 Pro
Its 2M window is about 2× larger, fitting roughly 3,000 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Gemini 3.1 Pro
At $2/$12 per 1M tokens it undercuts Claude Sonnet 5, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ Gemini 3.1 Pro
Larger 2M window fits more in one prompt.
Anyone whose priority is agentic workflows that plan, use tools, and run autonomously
→ Claude Sonnet 5
It is specifically built for that.
Anyone whose priority is largest mainstream production context (2m)
→ Gemini 3.1 Pro
That is its strongest area.
Claude Sonnet 5: where it fits
Anthropic's most agentic Sonnet, with near-Opus-4.8 performance at Sonnet prices; the default model on Free and Pro. Released June 30, 2026 by Anthropic, it is built for agentic workflows that plan, use tools, and run autonomously, multi-step coding, debugging, and tool use, everyday professional and knowledge work, and long-document analysis and reasoning.
Its trade-offs are real: lower peak accuracy than Opus 4.8 on the hardest tasks, and an updated tokenizer that can use 1.0-1.35x more tokens for the same text. At $3 in / $15 out per million tokens, it sits in the mid price band.
Gemini 3.1 Pro: where it fits
A 2M-token multimodal workhorse — huge breadth, but recall fades deep in the window. Released February 19, 2026 by Google, it is built for largest mainstream production context (2M), long video and document analysis, agentic reasoning (high ARC-AGI-2), and multimodal understanding.
Its trade-offs: long-context recall drops sharply past 256K, and premium price per token. At $2 in / $12 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
Claude Sonnet 5 and Gemini 3.1 Pro overlap enough that the right pick depends on your specific job. Gemini 3.1 Pro costs less per token; Gemini 3.1 Pro holds the larger context; and each leads in its own area — Claude Sonnet 5 for agentic workflows that plan, use tools, and run autonomously, Gemini 3.1 Pro for largest mainstream production context (2m). Rather than crowning one, run the same hard task through both once and let the results decide.
Want both Claude Sonnet 5 and Gemini 3.1 Pro without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.
Is Claude Sonnet 5 or Gemini 3.1 Pro better for coding?
Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Claude Sonnet 5 leans toward agentic workflows that plan, use tools, and run autonomously while Gemini 3.1 Pro leans toward largest mainstream production context (2m), and that positioning usually predicts which feels better on your codebase.
Which is cheaper, Claude Sonnet 5 or Gemini 3.1 Pro?
Gemini 3.1 Pro is cheaper — $3/$15 per 1M tokens vs $2/$12 per 1M tokens, roughly 1.5× apart on input.
Which has the bigger context window?
Gemini 3.1 Pro — 2M vs 1M, about 2× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both Claude Sonnet 5 and Gemini 3.1 Pro together?
Yes — a multi-model platform like LumiChats gives you Claude Sonnet 5, Gemini 3.1 Pro and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.
Which is newer, Claude Sonnet 5 or Gemini 3.1 Pro?
Claude Sonnet 5 — released June 30, 2026, about 4 months after Gemini 3.1 Pro.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.