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LLM Toolkit

Model comparison

Gemini 3.5 Flash vs Claude Sonnet 5

Verified pricing, context windows and real-workload costs for both models — computed from official provider rates as of 2026-08-25.

Cheaper input

Gemini 3.5 Flash

$1.50 /1M in

Cheaper output

Gemini 3.5 Flash

$9.00 /1M out

Bigger context

Gemini 3.5 Flash

1M tokens

Head to head

Spec Gemini 3.5 Flash Claude Sonnet 5
Input / 1M tokens $1.50 $3.00
Cached input / 1M — $0.3
Output / 1M tokens $9.00 $15.00
Context window 1M 200K
Provider Google Anthropic
Price verified 2026-08-25 2026-08-25

Monthly cost at three real workloads

Workload Gemini 3.5 Flash Claude Sonnet 5 Winner
Side-project chatbot 30K req · 2,000 in / 500 out · 40% cached $225.00/mo $340.20/mo Gemini 3.5 Flash
Coding agent 500K req · 12,000 in / 1,500 out · 70% cached $15,750/mo $17,910/mo Gemini 3.5 Flash
Bulk extraction 2,000K req · 800 in / 120 out · 20% cached $4,560/mo $7,536/mo Gemini 3.5 Flash

Computed from list prices verified 2026-08-25. Cache savings blend normal and cached input rates by the hit rate; models without published cached rates use the base input price. Adjust every parameter yourself on the API Cost Calculator.

Pick Gemini 3.5 Flash if…

  • Input cost dominates your bill — it charges $1.50 per 1M input vs $3.00.
  • You need the larger 1M context window.
  • You value its provider ecosystem and tooling.

Pick Claude Sonnet 5 if…

  • Output-heavy agent loops favor its $15.00 output rate.
  • Its 200K window covers your typical request with headroom.
  • You want cheaper total spend at your exact volumes — verify with the calculator above.

Frequently asked questions

Is Gemini 3.5 Flash cheaper than Claude Sonnet 5?

Gemini 3.5 Flash is cheaper on input at $1.50 per 1M tokens vs $3.00 — input pricing is 2.0× less expensive. On output, Gemini 3.5 Flash wins at $9.00 vs $15.00. At a balanced workload (100K requests, 2K in / 500 out), Gemini 3.5 Flash runs $750.00/mo vs $1,350/mo — a 1.8× difference.

Gemini 3.5 Flash vs Claude Sonnet 5: which has the bigger context window?

Gemini 3.5 Flash, with 1M tokens vs 200K — 5.0× more room. Filling Gemini 3.5 Flash's window once costs $1.50 at list price, vs $0.600 for the smaller window.

Should I switch from Gemini 3.5 Flash to Claude Sonnet 5?

Switch if your bottleneck matches Claude Sonnet 5's strengths: its 200K context fits your documents and its pricing profile. Stay on Gemini 3.5 Flash if input cost dominates your bill — Gemini 3.5 Flash charges $1.50 per 1M in. Test both with your real token counts before committing.

Keep comparing

Or measure your real usage with the AI Token Counter and browse all rates on the Pricing Comparison.