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Gemini 3.5 Flash-Lite API cost

At list prices from Google (Gemini API), Gemini 3.5 Flash-Lite costs $0.30 per million input tokens and $2.50 per million output tokens, with cached input at $0.03. Across the standard workloads below it would cost from $120.91 a month (long-form writing) to $1,083 a month (cached-prompt assistant).

It is the 4th cheapest of 13 models at 3 workloads, 5th cheapest of 13 for the long-form writing workload and 3rd cheapest of 12 for the cached-prompt assistant workload. Output tokens are 94% of the bill for long-form writing but 12% for long-document questions. Prompt caching takes the bill for the cached-prompt assistant workload from $2,068 to $1,083 a month, 48% less. Sent through the batch API, the short chat workload would cost $159.69 a month instead of $319.38.

Prices on this page last verified on Sources

Published prices

Google (Gemini API) list prices per million tokens. In our efficient tier.

Gemini 3.5 Flash-Lite prices per million tokens
Prompt lengthInputCached inputOutputBatch inputBatch cached inputBatch output
All prompt lengths$0.30$0.03$2.50$0.15$0.015$1.25

Cost at five standard workloads

The same traffic on every model, so the rank shows where Gemini 3.5 Flash-Lite sits. “vs cheapest” compares it with the cheapest model for that workload.

Gemini 3.5 Flash-Lite cost by workload
WorkloadRequests a dayTokens in / outPer 1,000 requestsPer monthVia batch APIRank, all modelsRank, efficient tiervs cheapest
Short chat10,0001,000 / 300$1.05$319.38$159.694th of 134th of 54.2× (Claude Haiku 5.5)
Long-document questions1,00030,100 / 500$10.28$312.68$156.344th of 134th of 53.2× (Claude Haiku 5.5)
Bulk tagging200,000400 / 10$0.145$882.08$441.044th of 134th of 53.2× (Claude Haiku 5.5)
Long-form writing5001,500 / 3,000$7.95$120.91$60.455th of 134th of 54.8× (Claude Haiku 5.5)
Cached-prompt assistant20,0008,000 / 400$1.78$1,083$541.423rd of 123rd of 43.9× (Claude Haiku 5.5)

Equal costs share a rank. “Via batch API” prices the same traffic with every request sent through the provider’s batch API, using its published batch prices.

Workload assumptions

Short chat

Short questions and answers at moderate volume.

Input tokens per request
Part of the promptTokensCachedWhy
Instructions300NoShort instructions, treated as uncached.
Message and recent turns700NoChanges with every request.
Total1,000None cached
Requests a day: 10,000
A popular in-app assistant.
Output tokens per request: 300
A reply of about 220 words.
Batch API: not used
Real-time replies.

These are stated assumptions for illustration, not measurements. Cached parts are assumed to be read from the prompt cache on every request. Token counts are the same for every model, although providers count tokens differently. Use the calculator to try your own figures.

Long-document questions

Long input with a short answer: most of the cost is input tokens.

Input tokens per request
Part of the promptTokensCachedWhy
Document30,000NoAbout 22,000 words, different every time.
Question100NoOne or two sentences.
Total30,100None cached
Requests a day: 1,000
A research or legal team asking questions of whole documents.
Output tokens per request: 500
An answer of about 370 words.
Batch API: not used
Real-time answers.

These are stated assumptions for illustration, not measurements. Cached parts are assumed to be read from the prompt cache on every request. Token counts are the same for every model, although providers count tokens differently. Use the calculator to try your own figures.

Bulk tagging

Very high volume with a tiny output: a label per item.

Input tokens per request
Part of the promptTokensCachedWhy
Instructions and labels300NoShort instructions, treated as uncached.
Item100NoA short text.
Total400None cached
Requests a day: 200,000
Items such as tickets, reviews or records tagged as they arrive.
Output tokens per request: 10
One label.
Batch API: not used
Tagged as items arrive.

These are stated assumptions for illustration, not measurements. Cached parts are assumed to be read from the prompt cache on every request. Token counts are the same for every model, although providers count tokens differently. Use the calculator to try your own figures.

Long-form writing

A short brief and a long answer: most of the cost is output tokens.

Input tokens per request
Part of the promptTokensCachedWhy
Brief and style notes1,500NoDifferent for each piece.
Total1,500None cached
Requests a day: 500
Articles, reports or long emails drafted a day.
Output tokens per request: 3,000
About 2,200 words.
Batch API: not used
Drafts are wanted straight away.

These are stated assumptions for illustration, not measurements. Cached parts are assumed to be read from the prompt cache on every request. Token counts are the same for every model, although providers count tokens differently. Use the calculator to try your own figures.

Cached-prompt assistant

A large fixed prompt read from the prompt cache on every request.

Input tokens per request
Part of the promptTokensCachedWhy
Instructions and tool definitions6,000YesThe same on every request, so read from the prompt cache.
Conversation and request2,000NoChanges with every request.
Total8,00075% cached
Requests a day: 20,000
A busy assistant with long instructions and tool definitions.
Output tokens per request: 400
A reply of about 300 words.
Batch API: not used
Real-time replies.

These are stated assumptions for illustration, not measurements. Cached parts are assumed to be read from the prompt cache on every request. Token counts are the same for every model, although providers count tokens differently. Use the calculator to try your own figures.

Your traffic looks different? Enter your own figures in the calculator.

Sources

Sources: aistudio.google.com (checked )

  • Tier: Provider text: "Our fastest, most cost-effective 3.5 model for high-throughput execution." Fastest and most cost-effective: efficient. aistudio.google.com (checked )

Prices are list prices as each provider publishes them, used unchanged. How the figures are calculated: methodology.