Cost per coding-agent request

Is Claude Opus 4.8 or Gemini 3.5 Flash cheaper for coding agents?

For coding agents, Claude Opus 4.8 costs 3.3x as much as Gemini 3.5 Flash per request ($0.16 vs $0.049 on our measured traffic), because Claude Opus 4.8 lists at $5 input, $0.50 cached input and $25 output per million tokens against $1.50, $0.15 and $9 for Gemini 3.5 Flash.

List prices: Anthropic pricing, OpenRouter listed price, checked 2026-10-13. Request costs: Standard Compute gateway data, 79,301 coding-agent requests from 75 users, Sep 13 to Oct 12, 2026. How we compute this

Run Claude Opus 5.5 and Gemini 3.8 Flash in your agent from $19/month

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Cost per coding-agent request, side by side

Cost at list price	Gemini 3.5 Flash	Opus 4.8
Prompt under 100K tokens50% of requests, 87% of input cached	$0.024	$0.079
Prompt of 100K to 272K39% of requests, 88% of input cached	$0.060	$0.20
Prompt over 272K tokens11% of requests, 86% of input cached	$0.13	$0.43
Average request	$0.049	$0.16
100 requests	$4.93	$16.23
Median session16 requests; a session ends after 10 idle minutes	$0.67	$2.25
A month of regular usemedian of 20 users active on 5+ days	$75.17	$249

Each logged request priced at the listed rates above for its own token counts, including cache reads and any higher rate for long prompts. Average output: 698 tokens per request.

Benchmarks, speed and latency, side by side

Artificial Analysis	Gemini 3.5 Flash	Opus 4.8
Intelligence Index10 evaluations, 0 to 100	33	42
Terminal-Bench 4.0agentic coding in a terminal	6.6%	21.7%
Output speedmedian	197 tokens/s	62 tokens/s
Time to first answer tokenincludes thinking time	17 s	66 s

Source: Artificial Analysis (artificialanalysis.ai). Measured variants: Gemini 3.5 Flash (High), speed on Google; Claude Opus 4.8 (Max), speed on Anthropic. Fetched October 13, 2026. Artificial Analysis runs Terminal-Bench 4.0 in its own setup, so its scores differ from the tbench.ai leaderboard.

What to watch for

Claude Opus 4.8 is superseded: Claude Opus 5.5 costs $0.11 per request. Gemini 3.5 Flash is superseded: Gemini 3.8 Flash costs $0.048 per request. The price is OpenRouter's listed rate on October 13, 2026, which can be a third-party host's; Google's own API may charge differently.

FAQ

Is Gemini 3.5 Flash cheaper than Claude Opus 4.8 for coding agents?

Yes, at the listed prices. 100 average coding-agent requests cost $4.93 on Gemini 3.5 Flash and $16.23 on Claude Opus 4.8. A median 16-request session costs $0.67 vs $2.25. Measured on 79,301 real coding-agent requests (Sep 13 to Oct 12, 2026).

How much does a month of Opus 4.8 vs Gemini 3.5 Flash cost?

For the median regular user in our data (1,478 requests in 30 days), about $249 on Claude Opus 4.8 and $75.17 on Gemini 3.5 Flash at list price. Heavier users pay proportionally more.

Claude Opus 4.8 vs Gemini 3.5 Flash: which is better for agents?

Claude Opus 4.8 scores higher on output quality (8.0/10 vs 6.8/10), while Gemini 3.5 Flash is the cheaper option. Claude Opus 4.8 is best for existing Opus 4.8 setups until they move to Opus 5.5; Gemini 3.5 Flash is best for existing Gemini 3.5 Flash setups until they move to 3.8 Flash. Live community votes on this page show what people actually prefer.

Can I switch between Claude Opus 4.8 and Gemini 3.5 Flash in the same agent?

Yes. Model-agnostic agents (Cline, Aider, OpenClaw, Hermes Agent, Kilo Code, OpenCode, Continue) let you swap models per task. Many people route hard tasks to the stronger model and routine work to the cheaper one.