GradingPen vs Turnitin

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.

The short answer

Free plan: GradingPen has one; Turnitin prices on request
Public API: Turnitin has one; not confirmed by us for GradingPen
Higher Trust score: Turnitin — 88 vs 72 for GradingPen
Best fit: GradingPen: Teachers grading large volumes of rubric-based essays · Turnitin: Universities and school districts that need similarity checking wired into Canvas, Moodle, Blackboard or D2L
Status: We could not check Turnitin — its site turns automated checks away; GradingPen was up on Sep 1, 2026

From our own records as of each tool's last check. Anything we have not confirmed is left out rather than guessed. How we verify

GradingPenAI essay and homework grading against custom rubrics, plus an AI tutor called Vero, for teachers and students.

TurnitinInstitutional similarity checking and AI-writing indicators for assignments, exams and manuscripts

Side by side

Fact	GradingPen	Turnitin
Category	Grading & Assessment	AI Detection & Humanizers
Pricing model	Freemium	Contact
Starts at	$7.99/mo	—
Public API	Not confirmed	Yes
Trust score	72 / 100	88 / 100
Platforms	Web	Web, API
Company	GradingPen	Turnitin, LLC
Launched	—	1998
Last verified	Sep 1, 2026	Sep 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

Turnitin

The incumbent for a reason: the submission database and the LMS integrations are what institutions buy, and no challenger matches either. Treat the AI-writing indicator as a prompt for a conversation, not a verdict; Turnitin itself now sells Clarity to show how a draft was written because a percentage alone keeps producing disputes, and the price only arrives after a sales call.

Pros

Largest comparison corpus of prior student submissions, which web-only checkers lack
LTI integrations with the major learning management systems
One contract covers grading, originality, exams and manuscript screening
Clarity adds process evidence about how a draft was written, not just a flag

Cons

No public pricing; every deal is an institutional quote
AI-writing detection produces false positives and has been contested by students
Student papers feed the comparison database, a long-running data-rights objection
The public site refuses automated fetches, which complicates monitoring

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 Turnitin if you need

Universities and school districts that need similarity checking wired into Canvas, Moodle, Blackboard or D2L
Publishers and research offices screening manuscripts through iThenticate
Assessment teams that want grading, proctored exams and integrity from one vendor