---
title: "Cheaper alternatives to GPT-6 Astra · Undominated.ai"
canonical: https://undominated.ai/alternatives/openai__gpt-6-astra/
description: "33 models score at least as high as GPT-6 Astra and cost no more on a balanced workload. 4 give up nothing measurable; the other 29 name what they drop. Measured prices and independent scores."
---

# Cheaper alternatives to GPT-6 Astra · Undominated.ai

> 33 models score at least as high as GPT-6 Astra and cost no more on a balanced workload. 4 give up nothing measurable; the other 29 name what they drop. Measured prices and independent scores.

# 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](/methodology/). 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](/models/openai__gpt-6-astra/), or [check GPT-6 Astra against the whole catalogue](/check/openai__gpt-6-astra/).

## 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](/significance/).
 - 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](/frontier/), and every other model something cheaper beats is [listed here](/alternatives/).