Recommendation for Business & professional
Business Writing
The best LLM for business writing is Claude Opus 4.6, which holds the top spot on LMArena's overall text arena with an Elo of 1501. For teams handling high email volume, it offers predictable per-message costs in the fractions of a cent range. Claude Fable 5 and Claude Opus 4.7 round out the top three, separated by only a few Elo points. Beyond raw preference scores, the decision gets more interesting when you factor in proofreading performance. Gemini 3.1 Pro and GLM 5.1 both beat Claude Sonnet variants on proofreading benchmarks, making them strong candidates for editing-heavy workflows where error detection matters more than drafting from scratch. Sonnet 4.6 has documented success catching mistakes in article rewrites, though Sonnet 5 is noted as the stronger of the two. For proposals and reports where tone and polish are paramount, the top-ranked Opus and Fable models are the safest bets based on human preference data.
About this recommendation
- Updated
- Jul 17, 2026
- Evidence through
- Jul 17, 2026
- Sources
- 11
- Revision
- v1
Claude Opus 4.6 sits at the top of LMArena's text rankings and is the most defensible choice for business writing where quality matters most. The cost estimates for email workflows make it practical even at scale.
Best when: You need top-tier writing quality for executive communications, proposals, or client-facing documents, and want predictable costs for high-volume email workflows.
Tips
- Holds the #1 ranking on LMArena's overall text arena with an Elo of 1501, indicating strong human preference for its output quality.
- Processing 10,000 emails costs an estimated $6.25 to $30.00, making per-email costs predictable for budget planning.
Claude Fable 5 trails Opus 4.6 by only eight Elo points on LMArena, making it a strong alternative for business writing tasks.
Best when: You want near-top-tier writing quality from the Claude family but may prefer Fable's characteristics for certain document types.
Tips
- Ranks #2 of 49 on LMArena's overall text arena with an Elo of 1493.
Claude Opus 4.7 holds the third spot on LMArena's text rankings. One user reported frustration with it for LaTeX presentation work, where it ultimately suggested a different tool, though this speaks more to tool selection than writing quality.
Best when: You want a top-three text model and are working on straightforward writing tasks rather than complex document formatting with LaTeX.
Tips
- Ranks #3 of 49 on LMArena's overall text arena with an Elo of 1490.
Watch out for
- A user found it error-prone for creating presentations in LaTeX, though the model correctly suggested Typst as a better alternative.
Gemini 3.1 Pro Preview stands out for proofreading workflows. It beats Claude Sonnet variants on an error-detection benchmark, making it valuable for editing and revision tasks.
Best when: Your primary need is proofreading, editing, or catching errors in existing business documents rather than drafting from scratch.
Tips
- Ranks #6 of 49 on LMArena's overall text arena with an Elo of 1479.
- Outperforms Claude Sonnet 5 on proofreading quality and cost in a multi-pass agent benchmark.
GLM 5.1 ranks #11 on LMArena but excels in proofreading. It beat Claude Sonnet variants on error detection in a benchmark, though one user noted GLM-5.2 made subtle mistakes in practice that required manual correction.
Best when: You need strong proofreading performance at a competitive price point and are willing to accept manual cleanup.
Tips
- Ranks #11 of 49 on LMArena's overall text arena with an Elo of 1466.
- Outperforms Claude Sonnet 5 on both quality and cost in a proofreading benchmark testing error detection in English text.
Claude Sonnet 4.6 sits at #17 on LMArena but has documented success in real-world article rewriting, catching errors that GLM-5.2 missed. It sits in a practical middle ground for business writing.
Best when: You need solid writing and editing performance at a lower cost tier and value a model with documented proofreading success.
Tips
- Successfully found and corrected all mistakes in an article rewrite by the second round, outperforming GLM-5.2 in practical testing.
- Ranks #17 of 49 on LMArena's overall text arena with an Elo of 1457.
Watch out for
- Lags behind Gemini 3.1 Pro and GLM 5.1 on proofreading benchmark performance.
Claude Sonnet 5 ranks lower on LMArena at #25, but benchmark testing confirms it improves on Sonnet 4.6 for proofreading tasks. Still, it trails Gemini and GLM alternatives.
Best when: You prefer the Claude ecosystem but don't need the top-tier Opus or Fable models, and want better proofreading than Sonnet 4.6 offers.
Tips
- Outperforms Sonnet 4.6 on proofreading tasks in benchmark testing.
- Ranks #25 of 49 on LMArena's overall text arena with an Elo of 1442.
Watch out for
- Inferior on both quality and cost to GLM 5.1, GLM 5.2, Gemini 3.1 Flash, and Gemini 3.1 Pro for proofreading work.
Frequently asked
- Which LLM is best for proofreading and editing business documents?
- Gemini 3.1 Pro and GLM 5.1 outperform Claude Sonnet models on proofreading benchmarks, catching more errors across multiple passes in an agent loop.
- How much does Claude Opus 4.6 cost for email responses at scale?
- Processing 10,000 emails with Claude Opus 4.6 costs approximately $6.25 to $30.00, assuming 200-word inputs and 50-word outputs per message.
- Is Claude Sonnet 4.6 good enough for business writing tasks?
- A user reported that Sonnet 4.6 successfully found and corrected all mistakes in an article rewrite by the second round, outperforming GLM-5.2 in practical testing.
- What is the difference between Claude Opus and Claude Fable for writing tasks?
- Both rank in the top three on LMArena's text arena (Elo 1501 and 1493 respectively), making both excellent for polished business writing, with Opus holding a slight edge in human preference scores.
Sources
- 1
“Ranks #1 of 17 on LMArena's overall text arena (Elo 1512), based on blind human preference votes.”
LMArena text arena · Benchmark · Jul 20, 2026 - 2
“Gemini says: "It would cost approximately $6.25 to $30.00 to have Claude Opus 4.6 respond to 10,000 emails, assuming a typical 200-word input and 50-word output per email."”
johndhi · Hacker News · Jun 26, 2026 - 3
“Ranks #2 of 17 on LMArena's overall text arena (Elo 1504), based on blind human preference votes.”
LMArena text arena · Benchmark · Jul 20, 2026 - 4
“Ranks #4 of 17 on LMArena's overall text arena (Elo 1499), based on blind human preference votes.”
LMArena text arena · Benchmark · Jul 20, 2026 - 5
“My experience is the same. It was agonizing directing Claude Code (Opus 4.7 at that time) to create a (non-mathematical) preso using LaTex. After banging my head against that wall for too long, I asked why this process (placing entities on the output PDF page according to specific requirements) was so error prone, and received the answer "LaTex is really the wrong tool for this job". I chose Typst from among the offered alternatives, and it has been a MUCH better experience. I switched my resum…”
cagey · Hacker News · Jun 16, 2026 - 6
“Ranks #9 of 17 on LMArena's overall text arena (Elo 1489), based on blind human preference votes.”
LMArena text arena · Benchmark · Jul 20, 2026 - 7
“I run a proofreading benchmark that tests how well models can find and fix errors in English text. They get several passes in a simple agent loop. Sonnet 5 is definitely better than Sonnet 4.6, but inferior on both quality and cost to GLM 5.1, GLM 5.2, Gemini 3.1 Flash, and Gemini 3.1 Pro. https: revise.io errata-bench”
artursapek · Hacker News · Jun 30, 2026 - 8
“Ranks #11 of 49 on LMArena's overall text arena (Elo 1466), based on blind human preference votes.”
LMArena text arena · Benchmark · Jul 16, 2026 - 9
“I have tried to rewrite an article with GLM-5.2 and with Sonnet 4.6. Completely different results as LLM is non-deterministic. But GLM-5.2 made a lot of subtle mistakes that needed to be corrected by hand. On the opposite, Sonnet found and corrected all mistakes in the second round. Similar situation was with planning and coding. GLM-5.2 seems to be good “on paper” but the real usage results was different. And I am not an attorney for Claude or GLM-5.2… :) But as I’ve been using LLM models dail…”
sixtyj · Hacker News · Jun 30, 2026 - 10
“Ranks #17 of 49 on LMArena's overall text arena (Elo 1457), based on blind human preference votes.”
LMArena text arena · Benchmark · Jul 16, 2026 - 11
“Ranks #25 of 49 on LMArena's overall text arena (Elo 1442), based on blind human preference votes.”
LMArena text arena · Benchmark · Jul 16, 2026
Rankings synthesized from community evidence and open benchmarks. See methodology. Not driven by vendor marketing.