vakati-tech.ai

// head_to_head

Gemma 4 31B vs Llama 3.1 8B Instruct

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

Llama 3.1 8B Instruct is the cheaper of the two; neither can be ranked on quality here.

Llama 3.1 8B Instruct does not have a published LiveBench run, so this comparison covers price, context and declared capabilities only. A missing score means "not evaluated", not "worse" — the right way to separate these two is an eval on your own workload.

google

Gemma 4 31B

Blended / 1M
$0.250
Context
262K
Released
Apr 2, 2026
Overall score
38.7
reasoningtool callingimage inputvideo input

meta-llama

Llama 3.1 8B Instruct

Blended / 1M
$0.057
Context
131K
Released
Jul 23, 2024
Overall score
Not evaluated
tool callingprompt caching

Specs and pricing

MetricGemma 4 31BLlama 3.1 8B Instruct
LiveBench overall

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

38.7—
Cost per point

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

$0.0017—
Blended price / 1M

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

$0.250$0.057win
Input price / 1M$0.200$0.050win
Output price / 1M$0.400$0.080win
Cached input / 1M

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

—$0.025
Context window262Kwin131K
Max output tokens16K118Kwin

Benchmarks by category

An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — Gemma 4 31B on top, Llama 3.1 8B Instruct below, both out of 100.

Long-horizon agentic
10.7
—
Coding
49.0
—
Reasoning
68.3
—
Browser
0.0
—
Data analysis
53.3
—
Research
44.4
—
Documents & design
58.4
—

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.

WorkloadGemma 4 31BLlama 3.1 8B Instruct
Support chatbot

1.2K in / 400 out × 200K requests

$80.00/mo$16.60/mo
RAG assistant

8K in / 600 out × 100K requests

$184.00/mo$34.80/mo
Coding agent

40K in / 4K out × 20K requests

$192.00/mo$32.40/mo
Document extraction

20K in / 1.5K out × 50K requests

$230.00/mo$54.75/mo
Bulk classification

500 in / 20 out × 5M requests

$540.00/mo$120.50/mo
Run these two through the cost calculator

Which should you pick?

You need to fit large documents in one call

Gemma 4 31B

Wider context window — 262K against 131K.

You are cost-constrained

Llama 3.1 8B Instruct

Cheaper on blended list price at $0.057 per million tokens.

Gemma 4 31B vs Llama 3.1 8B Instruct FAQ

Which is better, Gemma 4 31B or Llama 3.1 8B Instruct?

Llama 3.1 8B Instruct is the cheaper of the two; neither can be ranked on quality here. Llama 3.1 8B Instruct does not have a published LiveBench run, so this comparison covers price, context and declared capabilities only. A missing score means "not evaluated", not "worse" — the right way to separate these two is an eval on your own workload.

Is Gemma 4 31B cheaper than Llama 3.1 8B Instruct?

Llama 3.1 8B Instruct is cheaper. On a 3:1 input:output blend, Gemma 4 31B lists at $0.250 per million tokens and Llama 3.1 8B Instruct at $0.057 — Llama 3.1 8B Instruct is 4.3× cheaper. Input and output are priced separately — Gemma 4 31B charges $0.200 in and $0.400 out, Llama 3.1 8B Instruct charges $0.050 and $0.080 — so the model that looks cheaper flips depending on how output-heavy your workload is.

Does Gemma 4 31B or Llama 3.1 8B Instruct have a bigger context window?

Gemma 4 31B has the larger context window: 262K for Gemma 4 31B against 131K for Llama 3.1 8B Instruct. Note that a window you can fill is not a window you should fill — retrieval quality usually degrades well before the limit, and you pay for every token you put in it.

Do Gemma 4 31B and Llama 3.1 8B Instruct support prompt caching?

Llama 3.1 8B Instruct publishes a cached-input rate of $0.025 per million tokens against a full input rate of $0.050. The catalogue lists no separate cached rate for Gemma 4 31B, which means the provider does not price it separately here — not that caching is unavailable.

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.
  • Scores — LiveBench release 2026-10-25, 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.