---
title: "Cheaper alternatives to Claude Sonnet 4.5 · Undominated.ai"
canonical: https://undominated.ai/alternatives/anthropic__claude-sonnet-4.5/
description: "32 models score at least as high as Claude Sonnet 4.5 and cost no more on a balanced workload. 11 give up nothing measurable; the other 21 name what they drop. Measured prices and independent scores."
---

# Cheaper alternatives to Claude Sonnet 4.5 · Undominated.ai

> 32 models score at least as high as Claude Sonnet 4.5 and cost no more on a balanced workload. 11 give up nothing measurable; the other 21 name what they drop. Measured prices and independent scores.

# Cheaper alternatives to Claude Sonnet 4.5

Anthropic · LMArena 1438 · $6.00/M on a balanced workload · prices as of 2026-08-28

## 11 models are both better and cheaper, giving up nothing.

Of the 133 models carrying both an independent score and a published price at the same delivery mode, **32** score at least as high as Claude Sonnet 4.5 and cost no more under at least one workload. **30** of them are genuinely cheaper; the rest match the price and win on score alone. **11** match or beat it on every capability we hold — context, maximum output, input modes, tool use and extended reasoning. **21** 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 Claude Sonnet 4.5, it is not generated.

## Where it holds

| Workload | Claude Sonnet 4.5 $/M | Better and cheaper | With a trade |
| --- | --- | --- | --- |
| Balanced | $6.00 | 11 | 21 |
| Summarise | $2.83 | 11 | 21 |
| Chat | $6.99 | 11 | 21 |
| Code gen | $9.98 | 11 | 21 |
| Agentic | $3.19 | 11 | 21 |

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 | 1438 |
| --- | --- |
| Context window | 1M |
| Max output | 64K |
| Input modes | text, image, file |
| Tool use | yes |
| Extended reasoning | yes |

A replacement has to clear every line above, not just the score. [Full record for Claude Sonnet 4.5](/models/anthropic__claude-sonnet-4.5/).

## Better and cheaper, nothing given up 11

Each of these matches or beats Claude Sonnet 4.5 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 | Gemini 3.7 Flash Google | 1490.2 +52.2 | $0.750 | Balanced −88% Summarise −88% Chat −87% Code gen −88% Agentic −87% |
| 2 | Gemini 3.5 Flash Google | 1482.6 +44.6 | $3.38 | Balanced −44% Summarise −47% Chat −41% Code gen −41% Agentic −43% |
| 3 | Muse Spark 1.1 Meta | 1478.3 +40.3 | $2.00 | Balanced −67% Summarise −62% Chat −70% Code gen −70% Agentic −67% |
| 4 | Gemini 3.6 Flash Google | 1476.5 +38.5 | $1.50 | Balanced −75% Summarise −75% Chat −75% Code gen −75% Agentic −75% |
| 5 | Gemini 3.1 Pro Preview Google | 1479.5 +41.5 | $4.50 | Balanced −25% Summarise −30% Chat −22% Code gen −21% Agentic −24% |
| 6 | GPT-5.4 OpenAI | 1469.6 +31.6 | $5.63 | Balanced −6% Summarise −12% Chat −2% Code gen −2% Agentic −5% |
| 7 | Gemini 2.5 Pro Google | 1457.3 +19.3 | $3.44 | Balanced −43% Summarise −52% Chat −37% Code gen −36% Agentic −41% |
| 8 | Claude Sonnet 4.6 Anthropic | 1457.6 +19.6 | $6.00 | Balanced same price Summarise same price Chat same price Code gen same price Agentic same price |
| 9 | GPT-5.6 Sol OpenAI | 1454.2 +16.2 | $4.00 | Balanced −33% Summarise −33% Chat −33% Code gen −33% Agentic −33% |
| 10 | GPT-5.6 Terra OpenAI | 1446 tie | $4.50 | Balanced −25% Summarise −30% Chat −22% Code gen −21% Agentic −24% |
| 11 | Claude Sonnet 5 Anthropic | 1442.3 tie | $4.00 | Balanced −33% Summarise −33% Chat −33% Code gen −33% Agentic −33% |

## Cheaper and higher-scoring, but you give something up 21

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 |
| --- | --- | --- | --- | --- |
| Qwen3.8 Max Qwen | 1481.9 +43.9 | $3.00 | Balanced −50% Summarise −40% Chat −56% Code gen −57% Agentic −51% | no file input |
| GLM 5.3 Z.ai | 1476.9 +38.9 | $2.15 | Balanced −64% Summarise −57% Chat −68% Code gen −69% Agentic −63% | no image, file input |
| Kimi K3 Moonshot AI | 1476.3 +38.3 | $6.00 | Balanced same price Summarise same price Chat same price Code gen same price Agentic same price | no file input |
| MiMo-V2.5-Pro Xiaomi | 1465 +27 | $0.544 | Balanced −91% Summarise −88% Chat −93% Code gen −93% Agentic −92% | no image, file input |
| GLM 5.2 Z.ai | 1465.4 +27.4 | $1.83 | Balanced −70% Summarise −63% Chat −73% Code gen −74% Agentic −69% | no image, file input |
| GLM 5.1 Z.ai | 1464.1 +26.1 | $1.94 | Balanced −68% Summarise −61% Chat −71% Code gen −72% Agentic −67% | 1.0M → 205K context no image, file input |
| Qwen3.7 Plus Qwen | 1456.2 +18.2 | $0.560 | Balanced −91% Summarise −90% Chat −91% Code gen −91% Agentic −90% | no file input |
| Kimi K2.6 Moonshot AI | 1455 +17 | $1.71 | Balanced −71% Summarise −69% Chat −72% Code gen −73% Agentic −71% | 1.0M → 262K context no file input |
| Grok 4.5 xAI | 1452.3 +14.3 | $3.00 | Balanced −50% Summarise −39% Chat −56% Code gen −57% Agentic −50% | 1.0M → 500K context |
| Kimi K2.5 Moonshot AI | 1445.2 tie | $0.900 | Balanced −85% Summarise −85% Chat −85% Code gen −85% Agentic −85% | 1.0M → 262K context no file input |
| GLM 5 Z.ai | 1445.2 tie | $0.930 | Balanced −85% Summarise −81% Chat −86% Code gen −86% Agentic −84% | 1.0M → 205K context no image, file input |
| Qwen3.6 Max Preview Qwen | 1446.3 tie | $2.31 | Balanced −61% Summarise −55% Chat −56% Code gen −59% Agentic −44% | 1.0M → 262K context no image, file input |
| Gemma 4 31B Google | 1441.7 tie | $0.152 | Balanced −97% Summarise −97% Chat −97% Code gen −98% Agentic −97% | 1.0M → 262K context 64K → 16K max output no file input |
| Hy3 Tencent | 1441.2 tie | $0.144 | Balanced −98% Summarise −97% Chat −98% Code gen −98% Agentic −97% | 1.0M → 262K context no image, file input |
| Qwen3.8 27B Qwen | 1440.8 tie | $0.956 | Balanced −84% Summarise −85% Chat −83% Code gen −83% Agentic −83% | no file input |
| Grok 4.6 xAI | 1443.7 tie | $3.00 | Balanced −50% Summarise −37% Chat −55% Code gen −57% Agentic −47% | 1.0M → 500K context |
| GLM 4.6 Z.ai | 1439.8 tie | $0.875 | Balanced −85% Summarise −84% Chat −86% Code gen −86% Agentic −85% | 1.0M → 205K context no image, file input |
| DeepSeek V4 Pro 0423 DeepSeek | 1439.2 tie | $1.09 | Balanced −82% Summarise −76% Chat −86% Code gen −87% Agentic −84% | no image, file input |
| Qwen3.5 397B A17B Qwen | 1438.3 tie | $0.877 | Balanced −85% Summarise −83% Chat −83% Code gen −84% Agentic −79% | 1.0M → 262K context no file input |
| Inkling Thinking Machines | 1439.2 tie | $1.73 | Balanced −71% Summarise −69% Chat −72% Code gen −72% Agentic −70% | no file input |
| GPT-5.1 OpenAI | 1441.4 tie | $3.44 | Balanced −43% Summarise −52% Chat −37% Code gen −36% Agentic −41% | 1.0M → 400K context |

## 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 ±10.68 points, so a gap smaller than that is marked *tie* rather than an improvement — see [significance bands](/significance/).
 - 188 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/).