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GradingPen vs Grammarly

Two fact sheets from our own research, side by side — pricing, platforms, API access and status re-checked by us rather than quoted from the vendors. GradingPen starts at $7.99, Grammarly at $12. Both have a free tier.

GradingPenAI essay and homework grading against custom rubrics, plus an AI tutor called Vero, for teachers and students.GrammarlyGrammar, tone and rewriting help inside every app

Side by side

FactGradingPenGrammarly
CategoryGrading & AssessmentGrammar & Proofreading
Pricing modelFreemiumFreemium
Starts at$7.99 month$12 month
Public APINoNo
PlatformsWebWeb, Chrome Ext, Windows, macOS, iOS, Android
CompanyGradingPenSuperhuman
Launched—2009
Last verifiedSep 1, 2026Sep 6, 2026

What our research says

GradingPen

GradingPen is built for teachers who already grade against rubrics and want a first pass done in seconds rather than hours, with LMS integrations so it fits into an existing workflow. The free tier is a genuine trial with 15 real submissions rather than a locked demo, but unlimited use requires the annual Teacher Pro plan.

Pros

  • Grades against a teacher-supplied custom rubric, not a generic scale
  • Reads handwritten submissions in multiple languages
  • Integrates with major LMS and gradebook platforms
  • Free tier includes 15 real graded submissions, not just a demo

Cons

  • Teacher Pro is billed annually ($199/year) with no monthly option shown
  • Public REST API is listed as coming soon, not available yet
  • Student tutoring and teacher grading are billed as separate plans

Grammarly

Still the default for catching mistakes inside other people's software, but the free tier has quietly become an AI-prompt meter and the honest price is $30 unless you commit to a full year.

Pros

  • Runs inside the apps people already write in rather than as a separate editor
  • Free tier still covers spelling, grammar and tone detection with no time limit
  • Pro folds in plagiarism and AI-text detection that rivals charge for separately

Cons

  • The $12 headline is the annual rate; paying monthly costs $30
  • Free AI allowance is 100 prompts a month and depletes quickly
  • No public API, so it cannot be embedded in another product
  • Enterprise pricing is not published anywhere on the site

Which one fits

Choose GradingPen if you need

  • Teachers grading large volumes of rubric-based essays
  • Schools already using Google Classroom, Canvas, or Schoology
  • Students wanting on-demand tutoring alongside graded feedback

Choose Grammarly if you need

  • Anyone writing in a browser, Word or email who wants corrections in place
  • Teams enforcing a house style guide across people who are not writers
  • Non-native English speakers who want fluency rewrites, not just error flags

More comparisons

Browse all Grading & Assessment →