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Gemini 3.5 Flash vs GPT-5.6 Terra

Published LiveBench scores across all seven categories, live list pricing, context windows, and the measured cost of a point of capability — for both models, side by side.

OpenRouter + LiveBenchAll comparisonsFull leaderboard

GPT-5.6 Terra scores higher, Gemini 3.5 Flash costs less — it depends on your workload.

GPT-5.6 Terra is ahead by 3.3 points overall, and Gemini 3.5 Flash lists 33% cheaper per blended million tokens. Whether 3.3 points is worth that depends on how much a wrong answer costs you. Gemini 3.5 Flash also leads on measured cost per point of capability, at $0.1357 per point.

google

Gemini 3.5 Flash

Blended / 1M
$3.38
Context
1.0M
Released
May 19, 2026
Overall score
74.6
reasoningtool callingimage inputvideo inputfile inputaudio inputprompt caching

openai

GPT-5.6 Terra

Blended / 1M
$4.50
Context
1.1M
Released
Jul 9, 2026
Overall score
77.9
reasoningtool callingfile inputimage inputprompt caching

Specs and pricing

MetricGemini 3.5 FlashGPT-5.6 Terra
LiveBench overall

Mean of the seven LiveBench category scores, 0–100. Higher is better.

74.677.9win
Cost per point

Measured benchmark spend divided by overall score — dollars per point of capability.

$0.1357win$0.1939
Blended price / 1M

3:1 input:output mix, the usual shape of production traffic.

$3.38win$4.50
Input price / 1M$1.50win$2.00
Output price / 1M$9.00win$12.00
Cached input / 1M

Price of an input token served from the prompt cache, where the provider publishes one.

$0.150win$0.200
Context window1.0M1.1M
Max output tokens66K128Kwin

Benchmarks by category

An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — Gemini 3.5 Flash on top, GPT-5.6 Terra below, both out of 100.

Agentic coding
49.0
54.9
Codingtoo close to call
78.2
78.2
Reasoning
82.0
90.6
Mathematics
88.2
94.9
Data analysis
64.9
79.3
Language
84.6
82.9
Instruction following
75.6
64.6

What each one costs to run

Per-token prices are hard to feel. These are monthly list costs for both models across five workload shapes, using each provider's published cached-input rate where there is one.

WorkloadGemini 3.5 FlashGPT-5.6 Terra
Support chatbot

1.2K in / 400 out × 200K requests

$982.80/mo$1310.40/mo
RAG assistant

8K in / 600 out × 100K requests

$1200.00/mo$1600.00/mo
Coding agent

40K in / 4K out × 20K requests

$1164.00/mo$1552.00/mo
Document extraction

20K in / 1.5K out × 50K requests

$2107.50/mo$2810.00/mo
Bulk classification

500 in / 20 out × 5M requests

$3975.00/mo$5300.00/mo
Run these two through the cost calculator

Which should you pick?

You are running this at volume

Gemini 3.5 Flash

Lowest measured cost per point of capability at $0.1357 per point — the gap compounds with every request.

Quality matters more than the bill

GPT-5.6 Terra

Highest overall LiveBench score of the two at 77.9.

The workload is coding or agentic work

GPT-5.6 Terra

Leads on agentic coding — 54.9 against 49.0.

Gemini 3.5 Flash vs GPT-5.6 Terra FAQ

Which is better, Gemini 3.5 Flash or GPT-5.6 Terra?

GPT-5.6 Terra scores higher, Gemini 3.5 Flash costs less — it depends on your workload. GPT-5.6 Terra is ahead by 3.3 points overall, and Gemini 3.5 Flash lists 33% cheaper per blended million tokens. Whether 3.3 points is worth that depends on how much a wrong answer costs you. Gemini 3.5 Flash also leads on measured cost per point of capability, at $0.1357 per point.

Is Gemini 3.5 Flash cheaper than GPT-5.6 Terra?

Gemini 3.5 Flash is cheaper. On a 3:1 input:output blend, Gemini 3.5 Flash lists at $3.38 per million tokens and GPT-5.6 Terra at $4.50 — Gemini 3.5 Flash is 33% cheaper. Input and output are priced separately — Gemini 3.5 Flash charges $1.50 in and $9.00 out, GPT-5.6 Terra charges $2.00 and $12.00 — so the model that looks cheaper flips depending on how output-heavy your workload is.

Gemini 3.5 Flash vs GPT-5.6 Terra: which scores higher on benchmarks?

Gemini 3.5 Flash scores 74.6 and GPT-5.6 Terra scores 77.9 overall on LiveBench, the mean of its seven categories. That is a 3.3-point lead for GPT-5.6 Terra. Category scores differ from the overall figure — a model can lead on reasoning and trail on coding, which the per-category table above breaks out.

Which gives better value for money, Gemini 3.5 Flash or GPT-5.6 Terra?

Gemini 3.5 Flash. Cost per point divides the measured dollars LiveBench spent running the benchmark by the score it earned, so it captures something token pricing misses: a reasoning model can emit many times more tokens than its per-token rate suggests. Gemini 3.5 Flash works out at $0.1357 per point and GPT-5.6 Terra at $0.1939.

Does Gemini 3.5 Flash or GPT-5.6 Terra have a bigger context window?

They are effectively the same — 1.0M for Gemini 3.5 Flash and 1.1M for GPT-5.6 Terra.

Do Gemini 3.5 Flash and GPT-5.6 Terra support prompt caching?

Both publish a cached-input rate: $0.150 per million for Gemini 3.5 Flash and $0.200 for GPT-5.6 Terra, against full input rates of $1.50 and $2.00. On a workload with a long stable prefix — a system prompt, a tool schema, a retrieved corpus — that changes the economics more than the headline price does.

Related comparisons

How these numbers are produced

  • Price — provider list price from OpenRouter, refreshed every 15 minutes. “Blended” is a 3:1 input:output mix.
  • ScoresLiveBench release 2026-06-25, using their own category map. Each model shows its strongest published run. A blank means “not evaluated”, never “bad”.
  • Cost per point — the measured dollars LiveBench spent on the run, divided by the score it earned.
  • “Win” — awarded only past a threshold: one full point on a benchmark score, 10% on a price, 25% on a context window. Anything tighter reports as a tie, because effort settings alone move a LiveBench score by more than that.

Published benchmarks rank models on someone else's tasks. Before committing, see LLM & agent evaluation for building an eval on your own.