Comparison · Anthropic and Google

Claude Sonnet 5.5 vs Gemini 3.8 Flash

Listed API prices of Claude Sonnet 5.5 and Gemini 3.8 Flash turned into the cost of the same three standard tasks, with speed from our own test requests in the United States and what each provider’s API documentation says about features that break on a switch. Output quality and answer length are not compared.

Calculated impact cost per task and per month

For an L2 task (deep analysis over a 50,000-token document, 3 steps), Claude Sonnet 5.5 costs $0.348 and Gemini 3.8 Flash $0.131 at the prices listed in the United States on , so Claude Sonnet 5.5 is 166.7 % more than Gemini 3.8 Flash, counting visible output only, without cache discounts or hidden reasoning.

TaskClaude Sonnet 5.5, per taskGemini 3.8 Flash, per taskClaude Sonnet 5.5, per monthGemini 3.8 Flash, per monthClaude Sonnet 5.5 vs Gemini 3.8 Flash, per task
L1Micro-task (classification or strict JSON extraction)$0.0050per L1 task$0.0019per L1 task$73.00per month$27.38per month+166.7 %
L2Deep analysis over a 50,000-token document$0.348per L2 task$0.131per L2 task$5,080.80per month$1,905.30per month+166.7 %
L3Agentic coding loop, 15 steps$2.72per L3 task$1.02per L3 task$39,726.60per month$14,897.47per month+166.7 %

Calculated Per month: 20 tasks an hour around the clock, 730 hours.

Prices USD per 1M tokens

PriceClaude Sonnet 5.5Gemini 3.8 Flash
Input, per 1M tokens$2.00$0.750
Output, per 1M tokens$10.00$3.75
Price fromProvider's price list · source page PublishedProvider's price list · source page Published
Read · the United States · the United States
Context window1,000,000 tokens1,048,576 tokens

What can I use it for? six common tasks, our data checks

Quality on your task: not measured by Measured Lab yet.

TaskClaude Sonnet 5.5Gemini 3.8 Flash
Answer customer messagesFits on price and contextFits on price and context
Pull data from invoices and documents with strict JSON and page imagesFits on price and contextFits on price and context
Summarize documents and meetingsFits on price and contextFits on price and context
Translate contentFits on price and contextFits on price and context
Chat assistant on your websiteFits on price and contextFits on price and context
Write and review code with tool callsFits on price and contextFits on price and context
Tasks it fits6 of 66 of 6

Checks of our data for six common tasks: a published price, a context window and answer length for the task and, where the task needs them, strict JSON output, page images and tool calls; prices, cost a month and terms for each model on its model card. Compare models for your own task in the model picker.

Speed in the US Observed our test requests

In our test requests from the United States, the median time to the first answer token was 961 ms for Claude Sonnet 5.5 (Direct API · Anthropic) and 6,955 ms for Gemini 3.8 Flash (Direct API · Google).

Model and routeTime to first answer token, medianOutput speed, medianAnswers
Claude Sonnet 5.5Direct API · Anthropic961 ms range 363 ms–8,537 ms115 tokens/s range 67.7 tokens/s–244 tokens/s115 answers on 23 dates
Gemini 3.8 FlashDirect API · Google6,955 ms range 1,021 ms–10,510 ms200 tokens/s range 103 tokens/s–365 tokens/s95 answers on 19 dates

The same short request to every model, sent from a measurement point in the United States; medians of successful answers on at least 2 different dates, latest on . How we measure

What breaks when you switch Published provider documentation

Moving from Anthropic to Google, 1 of the 5 features may not carry over, by each provider’s documentation:

  • Cache covers tool definitions — Anthropic: yes; Google: not stated. Where the cache does not cover tool definitions, a long tool list is paid as fresh input on every request.

Moving from Google to Anthropic: every feature that Google’s documentation lists as supported is also listed as supported by Anthropic.

What each provider’s own API documentation says, read ; “not stated” is not the same as “no”. Quotes and sources: what breaks when you switch AI APIs.

All model comparisons · How we check prices