Paste your newsletter, get the Flesch reading-ease score, grade level, reading time, and lexical diversity - benchmarked against the niche your competitors compete in.
TL;DR. Most consumer newsletters should hit a Flesch score of 60-70, which maps to grade level 8-10. B2B and technical newsletters can stretch to grade 11-12. Reading time should sit at 2-4 minutes for general sends, 5-7 minutes for deep editorial. Lexical diversity above 0.55 reads as varied; below 0.40 reads as repetitive.
Four numbers, one verdict, three concrete suggestions.
0 (unreadable) to 100 (fifth-grader). Most newsletters target 60-70.
US grade level required to read it comfortably. 8-10 is the sweet spot for general audiences.
Calculated at 240 words per minute (screen-reading standard). Returned as minutes:seconds.
Unique-token ratio. High diversity reads varied; low diversity reads repetitive. Top overused tokens listed.
All four numbers are percentile-ranked against newsletters in your category - B2B SaaS, ecommerce, media, creator.
Top three sentences ranked by reading difficulty, with shorter rewrites.
Median values from the Newsletrix corpus. Updated quarterly.
| Niche | Median Flesch | Grade level | Reading time |
|---|---|---|---|
| B2B SaaS | 52 | 11.4 | 3:40 |
| Ecommerce | 71 | 7.8 | 1:50 |
| Media / news | 62 | 9.6 | 4:20 |
| Creator / personal | 74 | 7.2 | 2:55 |
| Fintech | 48 | 12.6 | 5:10 |
| Developer / DevTools | 44 | 13.1 | 5:50 |
Pick a target grade level, audit your last 10 sends, level the prose until you hit it.
Standardise tone across contributors with a shared score and a shared bar.
Catch translations that drift from the source's reading level.
Flesch 60-70, grade 8-10 for general audiences. B2B / technical can run 11-12. Above 13, casual readers drop off.
2-4 minutes for general, 5-7 for deep editorial. Under 90 seconds reads unfinished; over 10 minutes loses most readers.
Ratio of unique to total words. Above 0.55 reads varied; below 0.40 reads repetitive. The calculator returns it plus the overused tokens.
Returns scores for any language but flags non-English as English-calibrated. Localised formulas planned for 2026.
240 words per minute, the empirical screen-reading rate. Image-heavy emails subtract image scan time.
Yes. Signed-in users get automatic scoring on every analyzed newsletter plus niche benchmarks.
Join newsletter creators using AI-powered competitor intelligence to ship better content, faster.
No credit card required · Cancel anytime · All features on every plan