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Gemini 3.8 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 3.8 Flash costs less — it depends on your workload.

GPT-5.6 Terra is ahead by 2.1 points overall, and Gemini 3.8 Flash lists 3.0× cheaper per blended million tokens. Whether 2.1 points is worth that depends on how much a wrong answer costs you.

google

Gemini 3.8 Flash

Blended / 1M
$1.50
Context
1.0M
Released
Sep 2, 2026
Overall score
75.8
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 3.8 FlashGPT-5.6 Terra
LiveBench overall

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

75.877.9win
Cost per point

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

$0.1750$0.1939
Blended price / 1M

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

$1.50win$4.50
Input price / 1M$0.750win$2.00
Output price / 1M$3.75win$12.00
Cached input / 1M

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

$0.075win$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 3.8 Flash on top, GPT-5.6 Terra below, both out of 100.

Agentic codingtoo close to call
54.2
54.9
Coding
72.5
78.2
Reasoning
89.3
90.6
Mathematics
91.6
94.9
Data analysis
54.0
79.3
Language
87.8
82.9
Instruction following
81.4
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 3.8 FlashGPT-5.6 Terra
Support chatbot

1.2K in / 400 out × 200K requests

$431.40/mo$1310.40/mo
RAG assistant

8K in / 600 out × 100K requests

$555.00/mo$1600.00/mo
Coding agent

40K in / 4K out × 20K requests

$522.00/mo$1552.00/mo
Document extraction

20K in / 1.5K out × 50K requests

$997.50/mo$2810.00/mo
Bulk classification

500 in / 20 out × 5M requests

$1912.50/mo$5300.00/mo
Run these two through the cost calculator

Which should you pick?

Quality matters more than the bill

GPT-5.6 Terra

Highest overall LiveBench score of the two at 77.9.

You are cost-constrained

Gemini 3.8 Flash

Cheaper on blended list price at $1.50 per million tokens.

Gemini 3.8 Flash vs GPT-5.6 Terra FAQ

Which is better, Gemini 3.8 Flash or GPT-5.6 Terra?

GPT-5.6 Terra scores higher, Gemini 3.8 Flash costs less — it depends on your workload. GPT-5.6 Terra is ahead by 2.1 points overall, and Gemini 3.8 Flash lists 3.0× cheaper per blended million tokens. Whether 2.1 points is worth that depends on how much a wrong answer costs you.

Is Gemini 3.8 Flash cheaper than GPT-5.6 Terra?

Gemini 3.8 Flash is cheaper. On a 3:1 input:output blend, Gemini 3.8 Flash lists at $1.50 per million tokens and GPT-5.6 Terra at $4.50 — Gemini 3.8 Flash is 3.0× cheaper. Input and output are priced separately — Gemini 3.8 Flash charges $0.750 in and $3.75 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 3.8 Flash vs GPT-5.6 Terra: which scores higher on benchmarks?

Gemini 3.8 Flash scores 75.8 and GPT-5.6 Terra scores 77.9 overall on LiveBench, the mean of its seven categories. That is a 2.1-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 3.8 Flash or GPT-5.6 Terra?

They are close. Gemini 3.8 Flash costs $0.1750 per point of overall capability and GPT-5.6 Terra costs $0.1939, a difference small enough that workload shape will matter more than the rate.

Does Gemini 3.8 Flash or GPT-5.6 Terra have a bigger context window?

They are effectively the same — 1.0M for Gemini 3.8 Flash and 1.1M for GPT-5.6 Terra.

Do Gemini 3.8 Flash and GPT-5.6 Terra support prompt caching?

Both publish a cached-input rate: $0.075 per million for Gemini 3.8 Flash and $0.200 for GPT-5.6 Terra, against full input rates of $0.750 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.