Cheaper alternatives to GPT-6 Astra

OpenAI LMArena 1443.7 $20.00/M on a balanced workload prices as of 2026-09-19

4 models are both better and cheaper, giving up nothing.

Of the 136 models carrying both an independent score and a published price at the same delivery mode, 33 score at least as high as GPT-6 Astra and cost no more under at least one workload. 32 of them are genuinely cheaper; the rest match the price and win on score alone. 4 match or beat it on every capability we hold — context, maximum output, input modes, tool use and extended reasoning. 29 do not, and every row names what it drops.

Dominance is not a property of a model. It is a property of a model, a capability lens and a workload, and all three are named on every row. Scores are LMArena Elo, used under CC BY 4.0 from the official dataset; prices are blended per million tokens. A higher score is not a drop-in replacement.

This page is built from that comparison and nothing else. When no model is both better and cheaper than GPT-6 Astra, it is not generated.

Where it holds

Workload	GPT-6 Astra $/M	Better and cheaper	With a trade
Balanced	$20.00	4	29
Summarise	$9.44	4	29
Chat	$23.30	4	29
Code gen	$33.28	4	29
Agentic	$10.64	4	29

Workload mixes are defined on the methodology page. Cached input is priced at the cached rate, and reasoning tokens at the worse of the reasoning and output rates.

What you would be replacing

Intelligence	1443.7
Context window	1.1M
Max output	128K
Input modes	file, image, text
Tool use	yes
Extended reasoning	yes

A replacement has to clear every line above, not just the score. Full record for GPT-6 Astra, or check GPT-6 Astra against the whole catalogue.

Better and cheaper, nothing given up 4

Each of these matches or beats GPT-6 Astra on context, maximum output, input modes, tool use and reasoning, scores at least as high, and costs no more.

#	Model	Intelligence	$/M	Holds under
1	GPT-5.5 OpenAI	1465.6 +21.9	$11.25	Balanced −44% Summarise −47% Chat −41% Code gen −41% Agentic −43%
2	GPT-5.6 Sol OpenAI	1455.1 +11.4	$4.00	Balanced −80% Summarise −80% Chat −80% Code gen −80% Agentic −80%
3	GPT-5.4 OpenAI	1452.6 tie	$5.63	Balanced −72% Summarise −74% Chat −71% Code gen −70% Agentic −71%
4	GPT-5.6 Terra OpenAI	1446.2 tie	$4.50	Balanced −78% Summarise −79% Chat −77% Code gen −76% Agentic −77%

Cheaper and higher-scoring, but you give something up 29

These score at least as high and cost no more on the two plotted axes, and lose something that is not on them. Read the last column before switching.

Model	Intelligence	$/M	Holds under	What you give up
Claude Opus 5 Anthropic	1504.9 +61.2	$10.00	Balanced −50% Summarise −50% Chat −50% Code gen −50% Agentic −50%	1.1M → 1.0M context
Claude Opus 4.6 Anthropic	1503 +59.3	$10.00	Balanced −50% Summarise −50% Chat −50% Code gen −50% Agentic −50%	1.1M → 1.0M context
Claude Fable 5.1 Anthropic	1507.6 +63.9	$20.00	Balanced same price Summarise −2% Chat −1% Code gen under 1% less Agentic −4%	1.1M → 1.0M context
Gemini 3.8 Flash Google	1494.7 +51	$1.50	Balanced −93% Summarise −93% Chat −93% Code gen −93% Agentic −92%	1.1M → 1.0M context 128K → 66K max output
Gemini 3.7 Flash Google	1490.5 +46.8	$1.50	Balanced −93% Summarise −93% Chat −93% Code gen −93% Agentic −92%	1.1M → 1.0M context 128K → 66K max output
Muse Spark 1.3 Meta	1489.7 +46	$2.00	Balanced −90% Summarise −88% Chat −91% Code gen −91% Agentic −90%	1.1M → 1.0M context
Claude Opus 4.7 Anthropic	1490 +46.3	$10.00	Balanced −50% Summarise −50% Chat −50% Code gen −50% Agentic −50%	1.1M → 1.0M context
Claude Fable 5 Anthropic	1492.6 +48.9	$20.00	Balanced same price Summarise same price Chat same price Code gen same price Agentic same price	1.1M → 1.0M context
Muse Spark 1.1 Meta	1480.2 +36.5	$2.00	Balanced −90% Summarise −88% Chat −91% Code gen −91% Agentic −90%	1.1M → 1.0M context
Gemini 3.1 Pro Preview Google	1480.1 +36.4	$4.50	Balanced −78% Summarise −79% Chat −77% Code gen −76% Agentic −77%	1.1M → 1.0M context 128K → 66K max output
Gemini 3.6 Flash Google	1476.1 +32.4	$1.50	Balanced −93% Summarise −93% Chat −93% Code gen −93% Agentic −92%	1.1M → 1.0M context 128K → 66K max output
GLM 5.3 Z.ai	1475.1 +31.4	$1.40	Balanced −93% Summarise −92% Chat −94% Code gen −94% Agentic −93%	no file, image input
Gemini 3.5 Flash Google	1475.7 +32	$3.38	Balanced −83% Summarise −84% Chat −82% Code gen −82% Agentic −83%	1.1M → 1.0M context 128K → 66K max output
GLM 5.3 Flash Z.ai	1471.9 +28.2	$0.142	Balanced −99% Summarise −99% Chat −99% Code gen −99% Agentic −99%	no file input
Kimi K3 Moonshot AI	1472.3 +28.6	$3.40	Balanced −83% Summarise −83% Chat −83% Code gen −83% Agentic −83%	1.1M → 1.0M context no file input
GLM 5.2 Z.ai	1466.9 +23.2	$0.851	Balanced −96% Summarise −95% Chat −96% Code gen −96% Agentic −96%	1.1M → 1.0M context no file, image input
MiMo-V2.5-Pro Xiaomi	1464.8 +21.1	$0.544	Balanced −97% Summarise −96% Chat −98% Code gen −98% Agentic −98%	no file, image input
GLM 5.1 Z.ai	1462.4 +18.7	$1.48	Balanced −93% Summarise −91% Chat −93% Code gen −94% Agentic −92%	1.1M → 205K context no file, image input
Gemini 2.5 Pro Google	1457.8 +14.1	$3.44	Balanced −83% Summarise −86% Chat −81% Code gen −81% Agentic −82%	1.1M → 1.0M context 128K → 66K max output
Claude Opus 4.8 Anthropic	1460.8 +17.1	$10.00	Balanced −50% Summarise −50% Chat −50% Code gen −50% Agentic −50%	1.1M → 1.0M context
Claude Sonnet 4.6 Anthropic	1458.3 +14.6	$6.00	Balanced −70% Summarise −70% Chat −70% Code gen −70% Agentic −70%	1.1M → 1.0M context
Kimi K2.6 Moonshot AI	1454.9 +11.2	$1.71	Balanced −91% Summarise −91% Chat −92% Code gen −92% Agentic −91%	1.1M → 262K context no file input
Qwen3.7 Plus Qwen	1454.2 tie	$0.560	Balanced −97% Summarise −97% Chat −97% Code gen −97% Agentic −97%	1.1M → 1.0M context no file input
Grok 4.5 xAI	1450.1 tie	$3.00	Balanced −85% Summarise −82% Chat −87% Code gen −87% Agentic −85%	1.1M → 500K context
GLM 5 Z.ai	1446.3 tie	$0.930	Balanced −95% Summarise −94% Chat −96% Code gen −96% Agentic −95%	1.1M → 205K context no file, image input
Claude Opus 4.5 Anthropic	1450.5 tie	$10.00	Balanced −50% Summarise −50% Chat −50% Code gen −50% Agentic −50%	1.1M → 200K context 128K → 64K max output
Kimi K2.5 Moonshot AI	1445.6 tie	$0.900	Balanced −96% Summarise −95% Chat −95% Code gen −95% Agentic −95%	1.1M → 262K context no file input
Qwen3.6 Max Preview Qwen	1446.3 tie	$2.31	Balanced −88% Summarise −86% Chat −87% Code gen −88% Agentic −83%	1.1M → 262K context 128K → 66K max output no file, image input
DeepSeek V4 Pro 0423 DeepSeek	1444 tie	$0.528	Balanced −97% Summarise −96% Chat −98% Code gen −98% Agentic −98%	1.1M → 1.0M context no file, image input

What this compares, and what it leaves out

Quality is LMArena Elo, used under CC BY 4.0 from the official dataset. The 95% confidence interval on a difference between two scores is about ±10.54 points, so a gap smaller than that is marked tie rather than an improvement — see significance bands.
191 further models at this delivery mode carry a price but no independent score. They are absent from the comparison in both directions — unrated is not a zero, and an unmeasured model is neither an alternative nor a worse buy.
Retired models are never offered as an alternative, and a model only competes against its own delivery mode: batch trades latency for price, so it is not a like-for-like swap.
Nothing here measures latency, throughput, rate limits or how a model behaves on your prompts. Two models with the same index score are not interchangeable.
The models that nothing beats on both axes are on the value frontier, and every other model something cheaper beats is listed here.