What is the best alternative to Claude Opus 4.8?

o3 is the closest model that scores higher on the BenchLeader Index (61.0 against 60.6). For less money, Claude Opus 5.5 scores 69.2 at $8.00 per 1M tokens.

Is there a cheaper alternative to Claude Opus 4.8?

Yes: Claude Opus 5.5 (69.2, $8.00), Gemini 4 Carbon (68.9, $8.00) and GPT-6.1 Sol (67.2, $4.00), each within 4 Index points and cheaper than Claude Opus 4.8's $10.00.

Is there an open-source alternative to Claude Opus 4.8?

The best open-weights models on the BenchLeader Index are Kimi K3 (62.1), GLM-5 (60.2) and GLM 5.2 (60.1). You can download and run them yourself; check each licence on its model page.

How are these alternatives chosen?

From the models ranked on the BenchLeader Index today: the ones just above Claude Opus 4.8, cheaper ones within 4 points, ones at least 1.5× as fast within 4 points, and the best open-weights models. Prices are list prices blended three input tokens to one output.

Anthropic

Claude Opus 4.8 alternatives

Data as of 2 Nov 2026 · ranked on the BenchLeader Index

As of 2 Nov 2026, Claude Opus 4.8 by Anthropic scores 60.6 on the BenchLeader Index at $10.00 per 1M tokens blended. O3 scores higher (61.0); Claude Opus 5.5 is the best cheaper model within 4 points (69.2 at $8.00); GPT-5.6 Sol is at least 1.5× as fast at a similar score; Kimi K3 is the best open-weights option (62.1).

Scores higher

The closest models above Claude Opus 4.8 on the Index.

o3 OpenAI61.0 · $3.50
GPT-5.6 Terra OpenAI compare61.1 · $4.50
Gemini 3.6 Flash Google compare61.3 · $1.50

Cheaper, nearly as good

Within 4 Index points, for less per token.

Claude Opus 5.5 Anthropic compare69.2 · $8.00
Gemini 4 Carbon Google compare68.9 · $8.00
GPT-6.1 Sol OpenAI compare67.2 · $4.00
Gemini 4 Argon Google compare65.9 · $4.00
GPT-5.6 Sol OpenAI compare65.4 · $8.00

Faster

At least 1.5× the output speed, within 4 points.

GPT-5.6 Sol OpenAI compare65.4 · $8.00
GPT-6.1 Terra OpenAI65.2 · $2.00
Claude Sonnet 5.5 Anthropic compare65.1 · $4.00

Open weights

The best models whose weights you can run yourself.

Kimi K3 Moonshot AI62.1 · $6.00
GLM-5 Zhipu AI60.2 · $1.55
GLM 5.2 Zhipu AI60.1 · $2.15

Every alternative side by side

Model	Index	$ / 1M blended	Tokens / s	Why
Claude Opus 4.8 (this model)	60.6	$10.00	66	–
Claude Opus 5.5	69.2	$8.00	96	cheaper
Gemini 4 Carbon	68.9	$8.00	95	cheaper
GPT-6.1 Sol	67.2	$4.00	87	cheaper
Gemini 4 Argon	65.9	$4.00	83	cheaper
GPT-5.6 Sol	65.4	$8.00	127	cheaper, faster
GPT-6.1 Terra	65.2	$2.00	107	faster
Claude Sonnet 5.5	65.1	$4.00	137	faster
Kimi K3	62.1	$6.00	66	open weights
Gemini 3.6 Flash	61.3	$1.50	197	scores higher
GPT-5.6 Terra	61.1	$4.50	130	scores higher
o3	61.0	$3.50	160	scores higher
GLM-5	60.2	$1.55	62	open weights
GLM 5.2	60.1	$2.15	89	open weights

Prices are list prices blended three input tokens to one output; speeds are measured medians, credited on each model page. The Index is BenchLeader's own, from independent benchmarks.

Questions people ask

What is the best alternative to Claude Opus 4.8?: o3 is the closest model that scores higher on the BenchLeader Index (61.0 against 60.6). For less money, Claude Opus 5.5 scores 69.2 at $8.00 per 1M tokens.
Is there a cheaper alternative to Claude Opus 4.8?: Yes: Claude Opus 5.5 (69.2, $8.00), Gemini 4 Carbon (68.9, $8.00) and GPT-6.1 Sol (67.2, $4.00), each within 4 Index points and cheaper than Claude Opus 4.8's $10.00.
Is there an open-source alternative to Claude Opus 4.8?: The best open-weights models on the BenchLeader Index are Kimi K3 (62.1), GLM-5 (60.2) and GLM 5.2 (60.1). You can download and run them yourself; check each licence on its model page.
How are these alternatives chosen?: From the models ranked on the BenchLeader Index today: the ones just above Claude Opus 4.8, cheaper ones within 4 points, ones at least 1.5× as fast within 4 points, and the best open-weights models. Prices are list prices blended three input tokens to one output.