AI model comparison

Gemini 3.8 Flash vs Gemini 3.5 Flash

Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.

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.

Input / 1M
$0.75
Output / 1M
$3.75
Context
1.05M

Gemini 3.5 Flash is Google's high-efficiency multimodal model, bringing near-Pro level coding and reasoning at Flash-tier cost and speed.

Input / 1M
$1.50
Output / 1M
$9
Context
1.05M

At a glance

Quick verdict

How the two models stack up on the things people ask about most.

Lower price

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Gemini 3.8 Flash

2.2x cheaper for a typical chat

Higher intelligence score

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Gemini 3.8 Flash

40.9 vs 33.6 on Artificial Analysis

Larger context window

Tie

1.05M vs 1.05M tokens

Newer release

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Gemini 3.8 Flash

Released September 2, 2026

Benchmarks

Benchmark scores

Independent scores from Artificial Analysis. Higher is better.

Intelligence index

google logoGemini 3.8 Flash40.9
google logoGemini 3.5 Flash33.6

Coding index

google logoGemini 3.8 Flash76.3
google logoGemini 3.5 FlashNot available

Agentic index

google logoGemini 3.8 Flash40.2
google logoGemini 3.5 FlashNot available

Pricing

Gemini 3.8 Flash vs Gemini 3.5 Flash API pricing

Per-token API rates. Cheaper option highlighted.

Metricgoogle logoGemini 3.8 Flashgoogle logoGemini 3.5 Flash
Input tokensPer 1M tokens$0.75$1.50
Output tokensPer 1M tokens$3.75$9
Cached input (read)Per 1M tokens$0.08$0.15
Cache writePer 1M tokens$0.04$0.08
Web searchPer request$0.014$0.014

What it costs in practice

Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.

Chat message

2K in, 500 out

google logoGemini 3.8 Flash$3.38
google logoGemini 3.5 Flash$7.50

Coding task

30K in, 4K out

google logoGemini 3.8 Flash$37.50$17.25 cached
google logoGemini 3.5 Flash$81$40.50 cached

Long document summary

150K in, 2K out

google logoGemini 3.8 Flash$120$18.75 cached
google logoGemini 3.5 Flash$243$40.50 cached

Specs

Context window and capabilities

How much each model can read, how much it can write, and what it accepts as input.

Metricgoogle logoGemini 3.8 Flashgoogle logoGemini 3.5 Flash
Context window1.05M tokens1.05M tokens
Max output66K tokens66K tokens
Input typesAudio, File, Image, Text, VideoAudio, File, Image, Text, Video
Output typesTextText
Reasoning effort levelsHigh, Medium, LowHigh, Medium, Low, Minimal
Default reasoning effortMediumMedium
Release dateSeptember 2, 2026May 19, 2026

Features

Supported features

API features available for each model.

Metricgoogle logoGemini 3.8 Flashgoogle logoGemini 3.5 Flash
Tool callingSupportedSupported
Structured outputsSupportedSupported
JSON modeSupportedSupported
ReasoningSupportedSupported
TemperatureSupportedSupported
Stop sequencesSupportedSupported
Deterministic seedSupportedSupported
Verbosity controlNot supportedNot supported

Our take

Gemini 3.8 Flash is 2.2x cheaper for a typical chat. Gemini 3.8 Flash scores higher on the Artificial Analysis Intelligence Index (40.9 vs 33.6). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.

FAQ

Frequently asked questions

Is Gemini 3.8 Flash or Gemini 3.5 Flash cheaper?

Gemini 3.8 Flash is cheaper for a typical chat (2K input tokens and 500 output tokens). Gemini 3.8 Flash costs $0.75 per 1M input tokens and $3.75 per 1M output tokens, while Gemini 3.5 Flash costs $1.50 per 1M input tokens and $9 per 1M output tokens.

Which has a bigger context window, Gemini 3.8 Flash or Gemini 3.5 Flash?

Gemini 3.8 Flash supports up to 1.05M tokens of context, compared with 1.05M for Gemini 3.5 Flash.

Is Gemini 3.8 Flash smarter than Gemini 3.5 Flash?

On the Artificial Analysis Intelligence Index, Gemini 3.8 Flash scores 40.9 and Gemini 3.5 Flash scores 33.6, putting Gemini 3.8 Flash ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.

Can I use Gemini 3.8 Flash and Gemini 3.5 Flash at the same time?

Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Gemini 3.8 Flash and Gemini 3.5 Flash answer side by side and keep the better response.

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Why choose? Ask both.

Send one prompt to Gemini 3.8 Flash and Gemini 3.5 Flash at the same time. Compare the answers side by side and keep the best one.