Preference · EleutherAI

Pythia 1.5B on Arena Elo: score, rank and what it means

Pythia 1.5B scores 1097.8 on Arena Elo, placing it #600 of 600 models in the index. The benchmark average is 1349.9 and the leader is Claude Opus 4.5 Max at 1501.9.

Score
1097.8
0–100 scale
Rank
#600
of 600
Percentile
1th
within the index
Benchmark avg
1349.9
all models
Leader
1501.9
Claude Opus 4.5 Max
Gap to leader
404.1
points

Score distribution

The chart shows the top 10 models on Arena Elo, with Pythia 1.5B highlighted. Longer bars mean higher scores.

Claude Opus 4.5 Max 1501.9
GPT-5.2 Reasoning 1500.4
GPT-5.2 Turbo 1500.3
Claude Opus 4.5 Reasoning 1497.5
GPT-5.2 Max 1495.3
Gemini 3 Pro Turbo 1494.9
Grok 4 Max 1491.4
Claude Opus 4.5 1491.2
GPT-5.1 Pro 1490.0
Grok 4 Reasoning 1487.6

Top 10 leaderboard

#ModelProviderContextInput / 1MAvg score
1 Claude Opus 4.5 Max Anthropic 1000000 $20.90 87.8
2 GPT-5.2 Reasoning OpenAI 1000000 $20.98 87.5
3 GPT-5.2 Turbo OpenAI 1000000 $20.73 87.4
4 Claude Opus 4.5 Reasoning Anthropic 2000000 $20.91 88.2
5 GPT-5.2 Max OpenAI 1000000 $21.39 89.2
6 Gemini 3 Pro Turbo Google DeepMind 400000 $19.62 86.4
7 Grok 4 Max xAI 2000000 $19.70 86.6
8 Claude Opus 4.5 Anthropic 400000 $19.42 87.7
9 GPT-5.1 Pro OpenAI 200000 $19.77 87.8
10 Grok 4 Reasoning xAI 2000000 $19.67 87.8

What this score means

On Arena Elo, Pythia 1.5B sits at #600 of 600. The leader, Claude Opus 4.5 Max, scores 1501.9, so the gap to the top is 404.1 points. The median model in this index scores 1373.8, which puts Pythia 1.5B below the midpoint.

EleutherAI models average 1208.8 on this benchmark. Pythia 1.5B is 111.0 points below that provider line, so it is a weaker result than the average EleutherAI model.

Among small open-weight models, the average is 1224.7. Pythia 1.5B is 126.9 points below that group. This is the more useful comparison if you are shortlisting within the same tier rather than across the whole index.

Read a 1097.8 as a relative signal, not an absolute guarantee. Benchmark scores depend on prompt format, evaluation harness and contamination controls. Use this page to narrow the shortlist, then test the model on your own data.

Price context

At $0.10 per million input tokens, Pythia 1.5B is below the median input price of $4.00 across the 600 models scored on Arena Elo. The models immediately around it in the ranking are shown below so you can compare score and price together.

ModelProviderContextInput / 1MAvg score
Claude Opus 4.5 Max Anthropic 1000000 $20.90 87.8
GPT-5.2 Reasoning OpenAI 1000000 $20.98 87.5
GPT-5.2 Turbo OpenAI 1000000 $20.73 87.4
Claude Opus 4.5 Reasoning Anthropic 2000000 $20.91 88.2
GPT-5.2 Max OpenAI 1000000 $21.39 89.2
Gemini 3 Pro Turbo Google DeepMind 400000 $19.62 86.4

Other benchmarks for Pythia 1.5B

BenchmarkScoreRankPercentileRelative
MMLU-Pro 45.9 600 1th
GPQA Diamond 30.4 600 1th
SWE-bench Verified 20.7 596 1th
HumanEval 37.4 599 1th
MATH-500 32.5 600 1th
AIME 2025 15.8 600 1th
LiveCodeBench 21.2 599 1th
IFEval 52.0 597 1th
TruthfulQA 44.7 598 1th
HellaSwag 57.8 600 1th
MMMU 34.9 600 1th

FAQ

What score does Pythia 1.5B get on Arena Elo?

Pythia 1.5B scores 1097.8 on Arena Elo in this index. The benchmark average is 1349.9 and the top score is 1501.9.

How does Pythia 1.5B rank on Arena Elo?

It ranks #600 of 600 models, in the 1st percentile. The leader is Claude Opus 4.5 Max at 1501.9.

Is Pythia 1.5B good at Arena Elo?

It is below the median for this benchmark, so test it carefully before relying on it for this capability. The result should be read alongside its price and context window.

How is the Arena Elo score calculated?

Arena Elo is a preference benchmark. Scores in this index are modelled estimates on a 0–100 scale (or Elo for Arena), derived from capability tier and benchmark difficulty. They are not official leaderboard results.

What does Pythia 1.5B cost?

Pythia 1.5B costs $0.10 per million input tokens and $0.54 per million output tokens.

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