Sentence Length
Introduction
Sentence length is a crucial factor for content readability and thus also for SEO performance. Google evaluates not only the relevance of content but also its user-friendliness. Optimal sentence lengths significantly contribute to visitors staying longer on the page and better understanding the content.
What is Sentence Length?
Sentence length is typically measured by the number of words per sentence. It is an important indicator of the complexity and comprehensibility of a text. Various readability formulas consider sentence length as a central factor.
Measuring Sentence Length
Category
Words per Sentence
Readability
Target Audience
Very Easy
8-10 words
Very Good
Elementary School
Easy
11-15 words
Good
Middle School
Medium
16-20 words
Satisfactory
High School
Difficult
21-25 words
Challenging
Adults
Very Difficult
26+ words
Very Challenging
Experts
Optimal Sentence Lengths for SEO
Recommended Values
For SEO-optimized content, the following guidelines apply:
- Average sentence length: 12-18 words
- Short sentences: 8-12 words (for important statements)
- Long sentences: 20-25 words (maximum)
- Variation: Mix of short and long sentences
Impact on SEO
Direct SEO Factors
- User Experience Signals
- Time on page
- Bounce rate
- Scroll depth
- Readability Metrics
- Flesch Reading Ease Score
- Flesch-Kincaid Grade Level
- Automated Readability Index
- Mobile Usability
- Readability on small screens
- Touch-friendly display
Practical Optimization
Improving Sentence Structure
Short sentences for important statements:
- Use short sentences for key messages
- Maximum 15 words for call-to-actions
- One thought per sentence
Long sentences for explanations:
- Use longer sentences for detailed explanations
- Maximum 25 words
- Clear sentence structure with commas
Technical Implementation
Analysis Tools
- Automated Tools
- Yoast SEO (WordPress)
- RankMath
- SEMrush Writing Assistant
- Manual Analysis
- Word count in word processing programs
- Own calculations
- Online Tools
- Readable.io
- Hemingway Editor
- WebFX Readability Tool
Avoiding Common Mistakes
Typical Problems
- Too long sentences
- Over 30 words
- Nested subordinate clauses
- Unclear references
- Too short sentences
- Staccato style
- Missing connections
- Robotic language
- Missing variation
- Monotonous sentence structure
- No rhythmic alternation
- Boring texts
Mobile Optimization
Special Requirements
- Shorter sentences on mobile devices
- Larger font for better readability
- More white space between paragraphs
Responsive Sentence Lengths
Device
Recommended Sentence Length
Characters per Line
Special Features
Desktop
15-20 words
65-75
Standard readability
Tablet
12-18 words
50-65
Medium screen size
Smartphone
10-15 words
35-50
Short lines important
Measurement and Monitoring
KPIs for Sentence Lengths
- Average sentence length
- Distribution of sentence lengths
- Readability scores
- User engagement metrics
Best Practices
Content Strategy
- Target audience-oriented adaptation
- Technical content: Longer sentences allowed
- General content: Shorter sentences preferred
- Consider content format
- Blog articles: 12-18 words
- Product descriptions: 10-15 words
- Landing pages: 8-12 words
- Regular review
- Monthly content audits
- A/B tests for different sentence lengths
- Performance monitoring