// head_to_head

Claude Opus 5.5 vs UnslopNemo 12B

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

UnslopNemo 12B is the cheaper of the two; neither can be ranked on quality here.

UnslopNemo 12B 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.

anthropic

Claude Opus 5.5

Blended / 1M
$8.00
Context
1M
Released
Sep 22, 2026
Overall score
83.2
reasoningtool callingimage inputfile inputprompt caching

thedrummer

UnslopNemo 12B

Blended / 1M
$0.400
Context
1.0M
Released
Nov 8, 2024
Overall score
Not evaluated

Specs and pricing

MetricClaude Opus 5.5UnslopNemo 12B
LiveBench overall

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

83.2
Cost per point

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

$0.4474
Blended price / 1M

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

$8.00$0.400win
Input price / 1M$4.00$0.400win
Output price / 1M$20.00$0.400win
Cached input / 1M

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

$0.200
Context window1M1.0M
Max output tokens128K819Kwin

Benchmarks by category

An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — Claude Opus 5.5 on top, UnslopNemo 12B below, both out of 100.

Agentic coding
71.7
Coding
89.3
Reasoning
92.2
Mathematics
97.1
Data analysis
80.3
Language
86.3
Instruction following
65.7

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.

WorkloadClaude Opus 5.5UnslopNemo 12B
Support chatbot

1.2K in / 400 out × 200K requests

$2,286/mo$128.00/mo
RAG assistant

8K in / 600 out × 100K requests

$2,880/mo$344.00/mo
Coding agent

40K in / 4K out × 20K requests

$2,672/mo$352.00/mo
Document extraction

20K in / 1.5K out × 50K requests

$5,310/mo$430.00/mo
Bulk classification

500 in / 20 out × 5M requests

$10,100/mo$1,040/mo
Run these two through the cost calculator

Which should you pick?

You are cost-constrained

UnslopNemo 12B

Cheaper on blended list price at $0.400 per million tokens.

Claude Opus 5.5 vs UnslopNemo 12B FAQ

Which is better, Claude Opus 5.5 or UnslopNemo 12B?

UnslopNemo 12B is the cheaper of the two; neither can be ranked on quality here. UnslopNemo 12B 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 Claude Opus 5.5 cheaper than UnslopNemo 12B?

UnslopNemo 12B is cheaper. On a 3:1 input:output blend, Claude Opus 5.5 lists at $8.00 per million tokens and UnslopNemo 12B at $0.400 — UnslopNemo 12B is 20× cheaper. Input and output are priced separately — Claude Opus 5.5 charges $4.00 in and $20.00 out, UnslopNemo 12B charges $0.400 and $0.400 — so the model that looks cheaper flips depending on how output-heavy your workload is.

Does Claude Opus 5.5 or UnslopNemo 12B have a bigger context window?

They are effectively the same — 1M for Claude Opus 5.5 and 1.0M for UnslopNemo 12B.

Do Claude Opus 5.5 and UnslopNemo 12B support prompt caching?

Claude Opus 5.5 publishes a cached-input rate of $0.200 per million tokens against a full input rate of $4.00. The catalogue lists no separate cached rate for UnslopNemo 12B, 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.
  • 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.