Readability of Spanish Texts: Alternative Metrics to ‘Flesch Reading Ease’? – Screaming Frog

Posted on June 9, 2025

TL;DR Summary of Measuring Spanish Text Readability with SEO Tools

Readability impacts user engagement and SEO, but English metrics like Flesch Reading Ease don’t suit Spanish well due to language differences. The Flesch-Szigriszt index is a proven Spanish-specific readability formula that adjusts for longer sentences and syllables. Using custom JavaScript in Screaming Frog SEO Spider, you can accurately measure Spanish readability across full page content or targeted HTML elements. Consider combining readability scores with user behavior analysis to improve content clarity and boost SEO results.

Optimixed’s Overview: Enhancing Spanish Content Readability Analysis with Custom SEO Techniques

Understanding Readability and Its SEO Relevance

Readability measures how easily a text can be read and comprehended, influencing user retention and trust. SEO frameworks emphasize EEAT, content quality, and user experience, where clear text reduces friction and bounce rates. Since Spanish syntax and word structure differ significantly from English, applying English formulas like Flesch Reading Ease can produce inaccurate assessments.

Spanish-Specific Metrics for Readability

  • Flesch-Szigriszt Index: Developed for Spanish, this formula accounts for syllables per word and words per sentence, validated on Spanish corpora and easy to interpret.
  • Flesch-Fernández Huerta: A related metric, less commonly used today.
  • INFLESZ: A composite readability scale ideal for health and academic Spanish texts.

Implementing Readability Analysis in Screaming Frog SEO Spider

Since there is no built-in Spanish readability metric, you can create custom JavaScript snippets in Screaming Frog to calculate the Flesch-Szigriszt index:

  • Method 1: Analyze the entire <body> text after cleaning it for accurate readability scores.
  • Method 2: Use XPath to target specific page sections, ideal for focused content analysis.

Both original and simplified formulas are available, with minor score differences. Additionally, custom scripts can output readability classifications using the INFLESZ scale (e.g., “Muy difícil”, “Normal”).

Key Insights and Best Practices

  • Spanish readability scores tend to be higher than English due to linguistic differences, underscoring the need for language-specific metrics.
  • Full page content generally yields easier readability scores than targeted XPath content, as navigation and UI text influence results.
  • Combining readability analysis with user data (eye tracking, surveys) provides a more holistic view of content effectiveness.
  • Adapt readability thresholds based on audience expertise and content complexity to optimize engagement.

Overall, adapting SEO tools with Spanish-specific readability metrics improves content clarity and user connection, fostering better SEO performance and user loyalty.

Source: Screaming Frog by Mark Porter. Read original article.