Claude Sonnet 5 vs Gemini 3.8 Flash
A flagship against a flash tier that costs a fraction of it: the honest question is how much of your work actually needs the flagship.
What the numbers say
- Gemini 3.8 Flash is about 2.7x cheaper on output tokens (45.0 vs 120 credits per 1M).
- Gemini 3.8 Flash is the newer release (September 2026 vs June 2026).
Derived from the live registry Zeplik routes and bills against. Credits: 1 credit = $0.10, computed from the raw provider rate with a 1.20x margin.
Side by side
Claude Sonnet 5
Anthropic
Sonnet 5 is Anthropic's most capable Sonnet-class model, with frontier performance across coding, agents, and professional work.
- Provider
- Anthropic
- Context window
- 1M tokens
- Input price
- 24.0 credits / 1M tokens ($2.00 raw)
- Output price
- 120 credits / 1M tokens ($10.00 raw)
- Vision (image input)
- Yes
- Tool calling
- Yes
- Extended reasoning
- No
Best for
- Hard problems where answer quality matters more than cost: strategy, analysis, difficult writing
- Very long documents and codebases: a 1M-token window fits entire books or repositories in one conversation
- Working with images: screenshots, charts, photos and scanned documents alongside text
- Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows
Gemini 3.8 Flash
Gemini 3.8 Flash is Google's most intelligent Flash model with significant gains from 3.7 Flash across software engineering, agentic tasks, and multi-step reasoning.
- Provider
- Context window
- 1.0M tokens
- Input price
- 9.0 credits / 1M tokens ($0.75 raw)
- Output price
- 45.0 credits / 1M tokens ($3.75 raw)
- Vision (image input)
- Yes
- Tool calling
- Yes
- Extended reasoning
- No
Best for
- High-volume everyday tasks where speed and cost matter: summaries, drafts, quick questions
- Very long documents and codebases: a 1.0M-token window fits entire books or repositories in one conversation
- Working with images: screenshots, charts, photos and scanned documents alongside text
- Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows
Try both on Zeplik
The honest answer to most model debates is to run your own prompt on both. Zeplik puts Claude Sonnet 5 and Gemini 3.8 Flash in the same chat, so you can switch mid-conversation and compare answers on the work you actually do.
Frequently asked questions
- What is the difference between Claude Sonnet 5 and Gemini 3.8 Flash?
- Gemini 3.8 Flash is about 2.7x cheaper on output tokens (45.0 vs 120 credits per 1M). Gemini 3.8 Flash is the newer release (September 2026 vs June 2026).
- Is Claude Sonnet 5 or Gemini 3.8 Flash cheaper?
- Gemini 3.8 Flash is cheaper: 45.0 credits per million output tokens against 120. 1 credit = $0.10, computed from the raw provider rate with a 1.20x margin.
- Which has the larger context window, Claude Sonnet 5 or Gemini 3.8 Flash?
- Gemini 3.8 Flash, at 1.0M tokens against 1M.
- Can I use both Claude Sonnet 5 and Gemini 3.8 Flash on Zeplik?
- Yes. Zeplik is a multi-model chat, so both sit behind one account and you can switch between them mid-conversation to compare answers on your own prompt.
- Do Claude Sonnet 5 and Gemini 3.8 Flash need a paid plan?
- One of the two is open to free accounts; the other needs a paid plan (Plus or above).
Related comparisons
- Claude Opus 5.5 vs Claude Sonnet 5The current Anthropic tier decision: Opus 5.5 costs twice Sonnet 5 for an identical million-token window, so the question is entirely about depth per turn.
- GPT-6 Luna vs Gemini 3.8 FlashThe value tier at its current edge: GPT-6 Luna undercuts the newest Gemini Flash by seven and a half times on both legs, with a marginally larger window.
- GPT-6 Sol vs Claude Sonnet 5Priced identically at $2 in and $10 out, five percent apart on context: the closest like-for-like comparison in the catalogue, and a genuine toss-up on price alone.
- Gemini 3.8 Flash vs Gemini 3.7 FlashThe current Gemini Flash against the one it replaces, priced identically at $0.75 in and $3.75 out: a straight generational question with no cost to trade off.
- Grok 4.7 vs Claude Sonnet 5Grok 4.7 answers for roughly half Sonnet 5's output price; Sonnet 5 answers with twice the context. The trade is unusually clean.
- GPT-6 Astra vs Claude Sonnet 5Frontier against workhorse: whether GPT-6 Astra earns five times Sonnet 5's price on the work you actually send it.
Explore Zeplik
- 467 AI skillsReady-to-run expert methods that run on Claude Sonnet 5, Gemini 3.8 Flash or any other model.
- 997 integrationsConnect Gmail, Slack, GitHub, Notion and hundreds more so the assistant can work in your apps.
- Simple pricingPlus, Pro and Max plans with a monthly credit allowance that works across every model.