Gemini 3.1 Flash-Lite API Pricing: 1M Context + Thinking at $0.25/$1.50

Gemini 3.1 Flash-Lite offers 1M-token context, vision, and built-in thinking at a budget price. It bridges the gap between the ultra-cheap 2.5 Flash-Lite and the more capable 3.5 Flash-Lite.

Updated Aug 13, 2026 · 93 models tracked across 11 providers

TL;DR

Price: $0.25/M input, $1.50/M output — mid-tier in Google's Flash-Lite family
Context: 1M tokens — process entire books or codebases in one request
Capabilities: Vision, multimodal input, and built-in thinking/reasoning
Provider: Google AI Studio / Vertex AI
Best for: Reasoning tasks on a budget, document analysis, multimodal processing
Trade-off: 2.5x pricier than 2.5 Flash-Lite — choose based on whether you need thinking

Thinking on a Budget: Gemini 3.1 Flash-Lite is one of the cheapest models with built-in thinking/reasoning capabilities. At $0.25/$1.50, it's 6x cheaper than Gemini 3.5 Flash-Lite ($0.30/$2.50) while still offering thinking — making it ideal for reasoning tasks where cost matters more than peak quality.

Gemini 3.1 Flash-Lite Pricing Breakdown

Standard pricing at different monthly volumes:

Monthly Volume	Input Cost	Output Cost	Total (70/30 Split)
1M tokens	$0.25	$1.50	$0.63
10M tokens	$2.50	$15.00	$6.25
100M tokens	$25.00	$150.00	$62.50
1B tokens	$250.00	$1,500.00	$625.00

At 100M tokens/month with a 70/30 input/output split, Gemini 3.1 Flash-Lite costs $62.50 — significantly cheaper than the 3.5 Flash-Lite ($105) while still offering thinking capabilities.

Gemini 3.1 Flash-Lite vs Other Budget Models

Model	Input $/M	Output $/M	Context	Thinking	Provider
Gemini 2.5 Flash-Lite	$0.10	$0.40	1M	No	Google
Gemini 3.1 Flash-Lite	$0.25	$1.50	1M	Yes	Google
Gemini 3.5 Flash-Lite	$0.30	$2.50	1M	Yes	Google
GPT-5.4 nano	$0.20	$1.25	400K	No	OpenAI
Qwen 3.7 Flash	$0.03	$0.13	1M	No	Alibaba
DeepSeek V4 Flash	$0.14	$0.28	1M	No	DeepSeek

Gemini 3.1 Flash-Lite is the cheapest model with both 1M context and thinking. Qwen 3.7 Flash is cheaper but lacks thinking; Gemini 3.5 Flash-Lite has thinking but costs more.

Google Flash-Lite Family: Which One to Choose?

Model	Input $/M	Output $/M	Context	Thinking	Best For
Gemini 2.5 Flash-Lite	$0.10	$0.40	1M	No	High-volume, simple tasks
Gemini 3.1 Flash-Lite	$0.25	$1.50	1M	Yes	Reasoning on a budget
Gemini 3.5 Flash-Lite	$0.30	$2.50	1M	Yes	Best thinking quality

Decision guide: Need the absolute cheapest? → 2.5 Flash-Lite. Need thinking on a budget? → 3.1 Flash-Lite. Need the best thinking quality? → 3.5 Flash-Lite.

When to Use Gemini 3.1 Flash-Lite

🧠 Reasoning Tasks

Tasks that need step-by-step thinking — classification, extraction, analysis — at budget pricing. The built-in thinking improves accuracy without premium model costs.

📄 Document Analysis

Process long documents with reasoning about their content. 1M context handles entire books; thinking improves comprehension and summary quality.

👁️ Multimodal Processing

Analyze images, videos, or audio with reasoning capabilities. Vision inputs cost the same as text — no premium for multimodal.

🔍 RAG Applications

Large context + thinking means better reasoning over retrieved documents. Improved answer quality without the cost of premium models.

📊 Data Classification

Classify and categorize data with reasoning about edge cases. Thinking helps handle ambiguous inputs that simpler models get wrong.

💬 Customer Support

Handle complex support queries that need reasoning about context. Thinking improves response quality for nuanced customer issues.

Real-World Cost: Processing 25,000 Documents/Month

Suppose you're building a document analysis service that processes 25,000 documents per month, averaging 3,000 input tokens and generating 800 output tokens per document:

Model	Input Cost	Output Cost	Monthly Total
Gemini 2.5 Flash-Lite	$7.50	$8.00	$15.50
Gemini 3.1 Flash-Lite	$18.75	$30.00	$48.75
Gemini 3.5 Flash-Lite	$22.50	$50.00	$72.50
GPT-5.4 nano	$15.00	$25.00	$40.00
Qwen 3.7 Flash	$2.25	$2.60	$4.85

At $48.75/month, Gemini 3.1 Flash-Lite costs 3x more than 2.5 Flash-Lite but delivers thinking capabilities. For tasks where reasoning accuracy matters, the improved quality often justifies the cost difference.

Compare 93 AI Models Side by Side

Gemini 3.1 Flash-Lite is one of 93 models tracked on APIpulse. Compare pricing, context windows, and features across 11 providers.

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Frequently Asked Questions

How much does Gemini 3.1 Flash-Lite cost?

Gemini 3.1 Flash-Lite costs $0.25 per million input tokens and $1.50 per million output tokens. This places it between the cheaper 2.5 Flash-Lite ($0.10/$0.40) and the more capable 3.5 Flash-Lite ($0.30/$2.50).

What is the context window of Gemini 3.1 Flash-Lite?

Gemini 3.1 Flash-Lite has a 1M token context window, matching every other model in Google's Flash-Lite family. This lets you process long documents, codebases, or conversation histories in a single request.

Does Gemini 3.1 Flash-Lite support vision and thinking?

Yes. Gemini 3.1 Flash-Lite supports multimodal inputs (text, images, video, audio) and has built-in thinking/reasoning capabilities. This makes it more capable than the 2.5 Flash-Lite, which lacks thinking.

How does Gemini 3.1 Flash-Lite compare to 2.5 Flash-Lite?

3.1 Flash-Lite ($0.25/$1.50) is 2.5x more expensive than 2.5 Flash-Lite ($0.10/$0.40) on input and 3.75x on output. The extra cost buys thinking capabilities and improved reasoning. For simple tasks, 2.5 Flash-Lite is cheaper; for tasks needing reasoning, 3.1 Flash-Lite is the better choice.

Is Gemini 3.1 Flash-Lite being deprecated?

No. Gemini 3.1 Flash-Lite is actively available on Google AI Studio and Vertex AI. Google has released newer Flash-Lite models (3.5) but 3.1 remains available and is not scheduled for deprecation.

Gemini 2.5 Flash-Lite Pricing — Cheaper at $0.10/$0.40 but no thinking
Gemini 3.5 Flash-Lite Pricing — Better thinking at $0.30/$2.50
All Google Flash-Lite Models — Compare all Flash-Lite tiers
Qwen 3.7 Flash Pricing — Cheapest model at $0.03/$0.13
Full Model Rankings — All 93 models ranked by price