Which is cheaper, Gemini 3.5 Flash-Lite and GPT-6.1 Terra?

Gemini 3.5 Flash-Lite has the lowest input price. Per 1M input tokens: Gemini 3.5 Flash-Lite from $0.30 and GPT-6.1 Terra from $1.00.

Which has the larger context window, Gemini 3.5 Flash-Lite and GPT-6.1 Terra?

GPT-6.1 Terra has the largest context window: Gemini 3.5 Flash-Lite 1,048,576 tokens and GPT-6.1 Terra 1,050,000 tokens.

Can I switch between Gemini 3.5 Flash-Lite and GPT-6.1 Terra without changing my code?

Yes. All of them are served through FastRouter's OpenAI-compatible API, so switching is a change of the model parameter (google/gemini-3.5-flash-lite, openai/gpt-6.1-terra).

Gemini 3.5 Flash-Lite vs GPT-6.1 Terra

Side-by-side pricing per provider, context window, benchmark scores and speed, all on one OpenAI-compatible API.

Estimate monthly cost for these models

Gemini 3.5 Flash-Lite Googlegoogle/gemini-3.5-flash-lite

GPT-6.1 Terra OpenAIopenai/gpt-6.1-terra

Creator

Google

OpenAI

Released

Jul 21, 2026

Oct 26, 2026

Context window

1.05M

Max output

66K

128K

Input / 1MLowest provider price

$0.30

$1.00

Output / 1MLowest provider price

$2.50

$5.00

Providers

IntelligenceArtificial Analysis index

11.7

51.0

LatencyMedian time to first token

1.4s

—

ThroughputMedian tokens per second

<1 t/s

—

Accepts

Text, Image, Audio, Video, Files

Text, Image, Files

Produces

Text

Tool calling

Yes

Structured output

Yes

Reasoning

Yes

Gemini 3.5 Flash-Lite vs GPT-6.1 Terra: summary

Gemini 3.5 Flash-Lite and GPT-6.1 Terra are both available through FastRouter's OpenAI-compatible API, so switching between them is a change of model id, not a new integration.

Gemini 3.5 Flash-Lite, from Google, has a 1,048,576-token context window, costs from $0.30/1M input and $2.50/1M output tokens across 2 providers and scores 11.7 on the Artificial Analysis Intelligence Index.

GPT-6.1 Terra, from OpenAI, has a 1,050,000-token context window, costs $1.00/1M input and $5.00/1M output tokens and scores 51.0 on the Artificial Analysis Intelligence Index.

Gemini 3.5 Flash-Lite is the cheapest on input, 3.3× cheaper than the next model, GPT-6.1 Terra has the largest context window and GPT-6.1 Terra scores highest for intelligence.

Switch with one line

client = OpenAI(base_url="https://api.fastrouter.ai/api/v1", api_key="<FASTROUTER_API_KEY>") client.chat.completions.create(model="google/gemini-3.5-flash-lite", messages=[...]) # or client.chat.completions.create(model="openai/gpt-6.1-terra", messages=[...])

Full API docs

Frequently asked questions

More comparisons

Benchmark scores sourced from ArtificialAnalysis