English
chat.gemini_3_5_flash
google/gemini-3-5-flash
chat

The Gemini 3.5 Flash API is Google's fast, efficient multimodal model — a 1M-token context window, native input for text, images, audio, video and PDF, function calling, and structured JSON outputs, tuned for low latency and high throughput. The Gemini 3.5 Flash API is OpenAI-compatible: point any existing SDK at RouterBase and set the model to gemini-3-5-flash. Input at $1.05 / 1M tokens, output at $6.30 / 1M tokens, cache reads at $0.105 / 1M tokens — 5% below the standard rate, all through one REST endpoint.

Input
Gemini 3.5 Flash
max_tokens4096
temperature1
top_p1
presence_penalty0
frequency_penalty0
Gemini 3.5 Flash Online
Hi! I'm a helpful AI assistant. What can I do for you?

Gemini 3.5 Flash API: Chat

Use the Gemini 3.5 Flash API to run Google's fast, efficient multimodal model with a 1M-token context window.

The Gemini 3.5 Flash API is Google's speed-optimized multimodal model — a 1M-token context window, native input for text, images, audio, video, and PDF, function calling, and structured JSON outputs, tuned for low latency and high throughput. Routed through RouterBase, it is fully OpenAI-compatible: point any existing SDK at RouterBase's base URL, set the model to gemini-3-5-flash, and your first call goes through immediately.

Pricing is $1.05 / 1M input tokens, $6.30 / 1M output tokens, and $0.105 / 1M cached-input reads — 5% below the standard rate. One RouterBase key — no Google credentials required.

Why this model

Six reasons teams ship on the Gemini 3.5 Flash API

From fast multimodal inference to 5%-off pricing — what makes Gemini 3.5 Flash stand out.

1M-token context

Accepts up to 1 million tokens per request — long documents, multi-file code, or video transcripts fit in a single Gemini 3.5 Flash API call.

Native multimodal input

The Gemini 3.5 Flash API understands text, images, audio, video, and PDFs. Pass mixed media in one request to analyze, transcribe, or reason across modalities.

Fast & high-throughput

Tuned for low latency and high volume: the Gemini 3.5 Flash API delivers Flash-tier speed for chat, classification, extraction, and routing at scale.

Function calling & JSON

Define tools and request a JSON schema; the Gemini 3.5 Flash API returns structured tool calls and strictly valid JSON for reliable agent and extraction pipelines.

OpenAI-compatible endpoint

The Gemini 3.5 Flash API speaks the OpenAI chat-completions wire format. Point any OpenAI SDK at RouterBase — no Google SDK or separate credentials needed.

One key for 200+ models

The same RouterBase key that calls the Gemini 3.5 Flash API also routes to GPT-5, Claude Opus 4.8, GPT-4o mini, and 200+ other models — no per-provider credential management.

RouterBase dashboard preview
Quickstart

Get started with the Gemini 3.5 Flash API in 3 steps

From sign-up to your first response in under 5 minutes.

  1. Create a RouterBase API key

    Sign up and generate an API key — one key reaches the Gemini 3.5 Flash API and every other model in the catalog.

  2. Send your first message

    Point any OpenAI-compatible SDK at routerbase.com/v1 and set the model to gemini-3-5-flash. The response follows the standard chat-completions schema — streaming and multimodal input supported.

  3. Inspect usage

    Every response includes a detailed token breakdown — input, output, and cache-read tokens — so cost and cache-hit rate are visible on every call.

Get API Key Read docs
Pricing

Pay only for what you use

RouterBase passes through partner-tier pricing. Compared against the model's official published API rate.

Customer stories

What teams build with the Gemini 3.5 Flash API

Real production loads running on the Gemini 3.5 Flash API and the RouterBase model catalog.

Marcus Reyes
Marcus ReyesCTO, Paradigm AI

We route high-volume chat through the Gemini 3.5 Flash API — fast multimodal responses at scale, and the 5% RouterBase discount is pure margin.

Priya Lakshmi
Priya LakshmiFounder, Quillo

Native vision on the Gemini 3.5 Flash API replaced an OCR pipeline — one fast call captions and extracts, text and image together.

Thomas Beck
Thomas BeckStaff Engineer, Northbeam

Structured JSON outputs from the Gemini 3.5 Flash API killed our flaky parsing — strictly valid JSON every time, even on multimodal inputs.

Aoi Tanaka
Aoi TanakaML Lead, Daybreak Robotics

Flash-tier latency on the Gemini 3.5 Flash API let us move classification online. RouterBase makes it 5% cheaper still.

Jonas Keller
Jonas KellerIndie Developer

The 1M context on the Gemini 3.5 Flash API means I can throw whole docs at it and still get fast answers. No chunking glue.

Ethan Nguyen
Ethan NguyenHead of Engineering, Compound Studio

RouterBase puts the Gemini 3.5 Flash API and 200+ other models behind one key. Our team stopped filing requests for new provider accounts.

Sophia Martín
Sophia MartínCTO, Relay

We A/B the Gemini 3.5 Flash API against Pro per request — same SDK, one model field. Most traffic stays on Flash and latency dropped.

Lucas Fernandes
Lucas FernandesEngineering Manager, Light

We migrated 42 services to the Gemini 3.5 Flash API over a weekend. The only PR comment was 'wait, that's all?'.

David Okonkwo
David OkonkwoCo-founder, Figment

Cache reads at $0.105 / 1M on the Gemini 3.5 Flash API made our long-context features affordable. The ROI math was instant.

Frequently Asked Questions

Common questions about the Gemini 3.5 Flash API.

It is RouterBase's pass-through to Google's Gemini 3.5 Flash — a fast, efficient multimodal chat endpoint with a 1M-token context, native vision/audio/video input, function calling, and structured outputs, served via an OpenAI-compatible REST interface.