// alternatives · October 2026
Claude Sonnet 4.5 alternatives
Cheaper models that come close, budget substitutes, and the cheapest step up — chosen on published LiveBench scores and live list price, never on our opinion. Every model here supports tool calling and image input, as Claude Sonnet 4.5 does.
LiveBench hasn't published a run for Claude Sonnet 4.5. The strongest benchmarked model at a similar or lower price is GPT-6.1 Sol, scoring 84.1 overall.
Claude Sonnet 4.5: no published LiveBench run, $6.00 per 1M blended tokens, about $2,220/mo for a RAG assistant.
Benchmarked models at or below its price
Claude Sonnet 4.5 has no published LiveBench run, so these are the highest-scoring benchmarked models priced no more than 25% above it — a known quantity to test against.
| Model | Overall | vs Claude Sonnet 4.5 | Blended / 1M | RAG assistant | Context |
|---|---|---|---|---|---|
| GPT-6.1 Solopenai 33% cheaper. Head to head → | 84.1 | — | $4.00−33% | $1,440/mo | 1.1M |
| Claude Sonnet 5.5anthropic 33% cheaper. Head to head → | 80.0 | — | $4.00−33% | $1,440/mo | 1M |
| Gemini 4 Argongoogle 33% cheaper. Head to head → | 79.3 | — | $4.00−33% | $1,440/mo | 1.0M |
| GPT-6.1 Terraopenai 67% cheaper. Head to head → | 77.8 | — | $2.00−67% | $720.00/mo | 1.1M |
| DeepSeek V4.1 Flash 1017deepseek 91% cheaper. Head to head → | 74.0 | — | $0.525−91% | $194.40/mo | 1.0M |
| Kimi K3.1 Promoonshotai 33% cheaper. Head to head → | 71.3 | — | $4.00−33% | $1,480/mo | 1.0M |
Claude Sonnet 4.5 alternatives FAQ
What is the best alternative to Claude Sonnet 4.5?
GPT-6.1 Sol. 33% cheaper. Every suggestion supports tool calling and image input, like Claude Sonnet 4.5.
How alternatives are chosen
- Scores — LiveBench release 2026-10-25. Only models with a published run are suggested on quality; a missing model means “not evaluated”, not “worse”.
- Prices — live list prices from OpenRouter, blended 3:1 input:output. Monthly figures price a RAG assistant with the published cached-input rate where there is one.
- Same job — suggestions must support every capability Claude Sonnet 4.5 has among tool calling and image input. Other listings of the same model (free or batch tiers) are variants, not alternatives, and are left out.
A few points on a public benchmark can hide large differences on your own tasks. Shortlist here, then decide with an eval — how to build one.