--- title: "Is Claude Sonnet 4.5 still undominated? · Undominated.ai" canonical: https://undominated.ai/check/anthropic__claude-sonnet-4.5/ description: "Claude Sonnet 4.5: whether it is still undominated. If anything in this catalogue is both better and cheaper, it is named, as of Sep 23, 2026. Unrated stays unrated." --- # Is Claude Sonnet 4.5 still undominated? · Undominated.ai > Claude Sonnet 4.5: whether it is still undominated. If anything in this catalogue is both better and cheaper, it is named, as of Sep 23, 2026. Unrated stays unrated. # Is Claude Sonnet 4.5 a good deal? Whether anything in this catalogue beats Claude Sonnet 4.5 on both quality and price, and what you give up if it does. A computation on the current catalogue, not an opinion. 13 undominated of 136 · Sep 23, 2026 [1 · Choose & set workload](#check-input)[2 · Read verdict](#check-verdict)[3 · Inspect alternatives](#check-options) As of Sep 23, 2026, Claude Sonnet 4.5 is dominated for Balanced on LMArena. Gemini 3.8 Flash scores 56.4 higher and costs 75% less, with a covering envelope. 13 of 136 rated, priced standard models are undominated. [Inspect model evidence](/models/anthropic__claude-sonnet-4.5/) [Compare differences & requirements](/compare/?models=anthropic%2Fclaude-sonnet-4.5%2Cgoogle%2Fgemini-3.8-flash) Current model Claude Sonnet 4.5 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) Gemini 3.8 Flash is both better and cheaper than Claude Sonnet 4.5: 56.4 points higher on LMArena and 75% less per million tokens, $4.50 cheaper at this mix. [Claude Sonnet 4.5](https://undominated.ai/models/anthropic__claude-sonnet-4.5/) LMArena Elo · higher is better Scale starts at 1040 Elo ** 1438.3 Effective $/M · Balanced · lower is better ** $6.00/M [Gemini 3.8 Flash](https://undominated.ai/models/google__gemini-3.8-flash/) LMArena Elo · higher is better Scale starts at 1040 Elo ** 1494.7 Effective $/M · Balanced · lower is better ** $1.50/M Claude Sonnet 4.5 takes text, image, file, returns up to 64,000 tokens from a 1,000,000-token context, and is listed by 7 sellers. Compared against 136 rated, priced models on this lens: 13 models dominate it and give up nothing, 5 more dominate it but give something up. Claude Sonnet 4.5 scores 1438.3 at $6.00 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 | | --- | --- | --- | --- | | [Gemini 3.8 Flash](/models/google__gemini-3.8-flash/) | 1494.7 +56.4 | $1.50/M | 75% | | [Gemini 3.7 Flash](/models/google__gemini-3.7-flash/) | 1490.5 +52.2 | $1.50/M | 75% | | [Muse Spark 1.3](/models/meta__muse-spark-1.3/) | 1489.7 +51.4 | $2.00/M | 67% | | [Muse Spark 1.1](/models/meta__muse-spark-1.1/) | 1480.2 +41.9 | $2.00/M | 67% | | [Gemini 3.1 Pro Preview](/models/google__gemini-3.1-pro-preview/) | 1480.1 +41.8 | $4.50/M | 25% | | [Gemini 3.6 Flash](/models/google__gemini-3.6-flash/) | 1476.1 +37.8 | $1.50/M | 75% | | [Gemini 3.5 Flash](/models/google__gemini-3.5-flash/) | 1475.7 +37.4 | $3.38/M | 44% | | [Claude Sonnet 4.6](/models/anthropic__claude-sonnet-4.6/) | 1458.3 +20.0 | $6.00/M | 0% | | [Gemini 2.5 Pro](/models/google__gemini-2.5-pro/) | 1457.8 +19.5 | $3.44/M | 43% | | [GPT-5.6 Sol](/models/openai__gpt-5.6-sol/) | 1455.1 +16.8 | $4.00/M | 33% | | [GPT-5.4](/models/openai__gpt-5.4/) | 1452.6 +14.3 | $5.63/M | 6% | | [GPT-5.6 Terra](/models/openai__gpt-5.6-terra/) | 1446.2 +7.9 | $4.50/M | 25% | | [Claude Sonnet 5](/models/anthropic__claude-sonnet-5/) | 1442.2 +3.9 | $4.00/M | 33% | ## 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 | | --- | --- | --- | --- | | [GLM 5.3](/models/z-ai__glm-5.3/) | 1475.1 | $1.29/M | image, file | | [Kimi K3](/models/moonshotai__kimi-k3/) | 1472.3 | $6.00/M | file | | [GLM 5.3 Flash](/models/z-ai__glm-5.3-flash/) | 1471.9 | $0.237/M | file | | [GLM 5.2](/models/z-ai__glm-5.2/) | 1466.9 | $0.998/M | image, file | | [MiMo-V2.5-Pro](/models/xiaomi__mimo-v2.5-pro/) | 1464.8 | $0.544/M | image, file | 136 rated, priced standard models. Chartreuse is the frontier. Cobalt is the model you named, when it is not on the staircase. Copy watch URL [Open the frontier](/frontier/) The link keeps the model and mix, using the current catalogue. Monthly spend and switching cost stay in this browser tab and are left out of the link. ## Saved decision references Save the model, workload, catalogue date and capability-preservation rule in this browser. Spend, switching cost and bill contents are not saved. No account or notifications. 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. Save this reference ## Continue your investigation - [Build a shortlist](/compare/) - [Inspect alternatives](/alternatives/) - [Check billing conditions](/traps/) - [Read model evidence](/models/)