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Anthropic · premium

Is Claude Sonnet 4.5 good?

Claude Sonnet 4.5 places top-3 in 1 of 22 task areas we tested. It's strongest at summarization & meeting notes and weakest at content & brand. It's a premium option ($18/1M tokens).

Top-3 finishes
22/22
Task areas tested
$18.0
Per 1M tokens
Slow
Typical speed

Our take

Anthropic: Claude Sonnet 4.5 is a premium-tier model that we tested across 22 task areas. It performs best at Summarization & Meeting Notes, and is weakest at Content & Brand.

Strengths

Clarity Concision Usefulness Specificity Structure Tone

Weak spots

No wrapper text Appropriate caveats Timing accuracy Practical sequencing Visual design Voice and tone

How Claude Sonnet 4.5 ranks, task by task

Rank is the position in each field; Rating is the absolute quality bar. A model can be rated "Excellent" yet sit mid-table when the whole field is strong — and vice-versa.

Task area Rank
Summarization & Meeting Notes #2 of 44
Sales #7 of 44
Landing Pages #9 of 56
Frontend & Landing Pages #19 of 93
RAG, Safety & Grounding #8 of 35
Creative & Comedy #11 of 44
Data & Analytics #17 of 69
Knowledge & Docs #23 of 94
Executive Assistant #13 of 50
AI Strategy #16 of 50
Customer Support #15 of 43
Coding #19 of 52
Translation & Localization #17 of 44
Research & Competitive Analysis #18 of 44
Training & Education #21 of 44
Investor & Pitch #24 of 50
Presentations & Decks #22 of 44
Structured Output #23 of 43
Chef / Home Cooking #31 of 50
Legal & HR #29 of 44
Product & Project Management #30 of 44
Content & Brand #37 of 50

Industry benchmarks

Standardized third-party scores, shown for context — these are independent of our real-task tests.

Design Arena — human preference (avg Elo 1217)

3d 1232 svg 1166 dataviz 1203 gamedev 1231 website 1232 asciiart 1222 uicomponent 1215 codecategories 1233

Headline vs. real-world

Source: Artificial Analysis (artificialanalysis.ai) via OpenRouter (openrouter.ai/rankings). (2026-06-29) · Source: Design Arena (www.designarena.ai) via OpenRouter (openrouter.ai/rankings). (2026-06-29)

Like Claude Sonnet 4.5, but…

Cheaper

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Frequently asked

Is Claude Sonnet 4.5 any good?

Claude Sonnet 4.5 places top-3 in 1 of 22 task areas we benchmarked. It performs best at Summarization & Meeting Notes.

What is Claude Sonnet 4.5 best at?

Its strongest task areas are Summarization & Meeting Notes, Sales, Landing Pages.

Is there a cheaper alternative to Claude Sonnet 4.5?

Qwen3.5 Plus 2026-02-15 is 90% cheaper and stays competitive on quality across our benchmarks.

How we test & rank

Each model is scored on real tasks across 22 task areas by an LLM judge with deterministic checks. "Percentile" is this model's standing within each area's field; the cross-area figures are rank-based so quality and Elo scores are never mixed.

This page is Spring Prompt, running

We just did this for every model. Do it for your prompt.

The rankings above come from running real tasks through real models and scoring every output. Spring Prompt is that same engine — pointed at your prompt, your test cases, and your definition of good.

  • Generate test cases from your prompt — no eval set required to start.
  • Compare models side by side with quality, cost and latency in one matrix.
  • Optimise the winner until the scores say it's ready to ship.
Experiment · Cold outreach email

Prompt × model results

12 test cases · 3 evals
Claude Opus
GPT-5
Gemini
v1
7.1
6.8
7.4
v2
8.3
7.9
8.0
v3
9.2
8.6
8.4
Best combo: v3 × Claude Opus
9.2 quality · $0.004/run · 1.8s