Gemini 3.8 Flash

Overview

Gemini 3.8 Flash is a generally available Gemini 3-series model released by Google on September 2, 2026. It is positioned for long-horizon software engineering, autonomous agents, and complex knowledge workflows, with a 1M-token input window and configurable reasoning effort.

Key Features

• Long-Horizon Agentic Execution: Designed for multi-step planning, iterative tool use, and verification across extended software-engineering and enterprise workflows.
• Configurable Thinking: Supports low, medium, and high thinking levels; medium is the default, while minimal is rejected.
• Native Multimodal Input: Accepts text, images, video, audio, and PDFs within a 1,048,576-token input limit and produces up to 65,536 text tokens.
• Broad Tool Support: Supports function calling, structured outputs, code execution, File Search, URL context, Search and Maps grounding, and Computer Use in preview.

Best Use Cases

• Agentic Software Engineering: Repository analysis, multi-file implementation, debugging, and migration workflows that require repeated reasoning and tool calls.
• Complex Knowledge Work: Long-form analysis and report generation across large document sets, structured data, and domain-specific evidence.
• Multimodal Analysis: Understanding documents, screenshots, charts, video, and audio together with text instructions.
• Tool-Orchestrated Applications: Agents that combine custom functions with code execution, search, URL retrieval, file search, or computer interaction.
• Asynchronous Bulk Processing: Classification, extraction, evaluation, and other delay-tolerant workloads that can use Batch or Flex inference.

Capabilities and Limitations

Capability	Description
Reasoning	Supports low, medium, and high thinking levels, with medium as the default. Higher effort can improve difficult multi-step work but may increase token consumption and latency.
Coding	Optimized for long-horizon software-engineering and agentic coding workflows. Google's release materials report gains over Gemini 3.7 Flash; provider-run evaluations are not production guarantees.
Multimodal	Accepts text, image, video, audio, and PDF input and produces text output.
Context Window	1,048,576 input tokens.
Max Output	65,536 tokens.
Tool Use	Function calling, structured outputs, code execution, File Search, URL context, Search and Maps grounding, and Computer Use (Preview).
Knowledge Cutoff	March 2026 overall; Google notes that knowledge in some domains may be limited to January 2025. Use grounding for newer or time-sensitive information.

Known Limitations

• The model can hallucinate, and Google notes that occasional slowness or timeout issues may occur.
• Difficult tasks and higher thinking levels may consume more reasoning and output tokens than earlier Flash workflows; applications should tune effort to their latency and cost targets.
• minimal thinking is unsupported. Legacy sampling parameters including temperature, top_p, and top_k are ignored, and prefilled model turns are rejected.
• Computer Use remains a preview capability, and the model does not support native image generation or native audio generation.

Pricing

Model	Input (Credits/Token)	Cache Write (Credits/Token)	Cache Read (Credits/Token)	Output (Credits/Token)	Web Search (Credits/Use)
Gemini 3.8 Flash	0.75	0.75	0.075	3.75	14,000

Explicit cache storage costs 0.50 Credits/Token per hour through December 31, 2026, and 1.00 Credits/Token per hour starting January 1, 2027.