---
title: "Is GPT-6 Astra still undominated? · Undominated.ai"
canonical: https://undominated.ai/check/openai__gpt-6-astra/
description: "GPT-6 Astra: whether it is still undominated. If anything in this catalogue is both better and cheaper, it is named, as of Sep 19, 2026. Unrated stays unrated."
---

# Is GPT-6 Astra still undominated? · Undominated.ai

> GPT-6 Astra: whether it is still undominated. If anything in this catalogue is both better and cheaper, it is named, as of Sep 19, 2026. Unrated stays unrated.

# Is GPT-6 Astra a good deal?

Whether anything in this catalogue beats GPT-6 Astra on both quality and price, and what you give up if it does. A computation on the current catalogue, not an opinion.

6 undominated of 137 · Sep 19, 2026

As of Sep 19, 2026, GPT-6 Astra is dominated for Balanced on LMArena. GPT-5.5 scores 21.9 higher and costs 44% less, with a covering envelope. 6 of 137 rated, priced standard models are undominated.

 Current model

GPT-6 Astra

 Balanced

3 tokens in per 1 out

 Balanced Summarise Chat Code gen Agentic
 Monthly spend (USD) Used only to say how many months a named switching cost would take to earn back. Leave blank to skip. Switching cost (USD) 137 rated, priced standard models. Chartreuse is the frontier. Cobalt is the model you named, when it is not on the staircase.

GPT-5.5 is both better and cheaper than GPT-6 Astra: 21.9 points higher on LMArena and 44% less per million tokens, $8.75 cheaper at this mix.

 [GPT-6 Astra](/models/openai__gpt-6-astra/)

LMArena Elo

 **

1443.7

Effective $/M · Balanced

 **

$20.00/M

 [GPT-5.5](/models/openai__gpt-5.5/)

LMArena Elo

 **

1465.6

Effective $/M · Balanced

 **

$11.25/M

GPT-6 Astra takes file, image, text, returns up to 128,000 tokens from a 1,050,000-token context, and is listed by 5 sellers.

Compared against 137 rated, priced models on this lens: 4 models dominate it and give up nothing, 5 more dominate it but give something up. GPT-6 Astra scores 1443.7 at $20.00 per million tokens for this mix.

## Envelope-safe replacements

Each row scores at least as high, costs no more, and covers this model’s context, output, modalities, tools, and reasoning. A cheaper narrower model is not listed here.

| Model | LMArena | Effective $/M | You save |
| --- | --- | --- | --- |
| GPT-5.5 | 1465.6 +21.9 | $11.25/M | 44% |
| GPT-5.6 Sol | 1455.1 +11.4 | $4.00/M | 80% |
| GPT-5.4 | 1452.6 +8.9 | $5.63/M | 72% |
| GPT-5.6 Terra | 1446.2 +2.5 | $4.50/M | 78% |

## Higher score, lower price, named losses

Not a drop-in. The loss is why these are not a recommendation.

| Model | LMArena | Effective $/M | You give up |
| --- | --- | --- | --- |
| Claude Fable 5.1 | 1507.6 | $20.00/M | context |
| Claude Opus 5 | 1504.9 | $10.00/M | context |
| Claude Opus 4.6 | 1503.0 | $10.00/M | context |
| Gemini 3.8 Flash | 1494.7 | $1.50/M | context, max output |
| Claude Fable 5 | 1492.6 | $20.00/M | context |

Copy watch URL [Open the frontier](/frontier/)

This page does not mail you. The URL is the watch: same model, same mix, current catalogue.

## Saved decision references

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Constraint: replacements must preserve the model’s capabilities; any losses remain named trade-offs.

Historical decisions cannot be fully replayed from saved references: past prices, scores and capability evidence are not stored.

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