Independently agent-testedAnthropic · OpenAI · Gemini · Grok
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Bench test · AI Writing

Grammarly vs Sudowrite

Same rack, same rubric, four independent agents. Here's how they measure up — and which we'd pick.

GrammarlySudowrite
consensus
score8.9/10
score8.5/10
agents won2 / 40 / 4
fromCustomCustom
free tiernono
categoryAI WritingAI Writing

Agent panel — head to head

Anthropic8.27.8
OpenAI8.58.5
Gemini9.39.3
Grok9.58.5

Grammarly

  • Catches errors missed by other tools
  • Improves writing clarity and professionalism
  • Works across multiple platforms seamlessly
  • Premium features require paid subscription
  • Can be overly cautious with style suggestions
  • Occasional false positives in corrections
Grammar and spelling correctionTone detection and adjustmentClarity and readability suggestionsPlagiarism detectionAudience-specific writing guidanceBrowser and app integration

Sudowrite

  • Tailored specifically for creative fiction rather than general writing
  • Helps overcome writer's block with inspiring suggestions
  • Improves writing speed and productivity
  • Requires human oversight to maintain authentic voice and quality
  • Subscription-based pricing model
  • AI-generated content may need significant editing and refinement
AI-powered story generation and scene expansionCharacter development and dialogue suggestionsRewriting and editing assistanceBrainstorming tool for plot ideasReal-time writing feedbackIntegration with word processors

Custom · no free tier

Try Grammarly

Custom · no free tier

Try Sudowrite

Verdict

Grammarly takes it — 8.9 to 8.5.

The panel gave Grammarly the edge on 2 of 4 agents.