DET
DET Pro pricing

Build your score with DET Pro.

Ten full-length practice tests, detailed speaking and writing feedback, and unlimited grading. Choose 7, 30, or 90 days.

Cancel anytime Secure Stripe checkout Same Pro features in every plan

PrepEx is a member of the Duolingo English Test Global Partner Network.

Short sprint

DET Sprint

Focused access for the final week before test day.

$9.99/ 7 days

Renews every 7 days until canceled.

  • 10 full-length practice tests and the complete Pro library
  • 1,400 DET Petra credits every 7 days
  • Unlimited objective grading and AI evaluation
  • Detailed speaking and writing feedback
  • Full history, patterns, and recommendations

Recurring subscription. Cancel anytime.

Most popular

DET Pro

A full month of guided, unlimited preparation.

$19.99/ 30 days

Renews every 30 days until canceled.

  • 10 full-length practice tests and the complete Pro library
  • 6,000 DET Petra credits every 30 days
  • Unlimited grading across all four sections
  • Detailed AI speaking and writing analysis
  • Dashboard, error patterns, and recommendations

Recurring subscription. Cancel anytime.

Best value

Three-month Pro

A longer runway for complete exam preparation.

$29.99/ 90 days

Renews every 90 days until canceled.

  • 10 full-length practice tests and the complete Pro library
  • 18,000 DET Petra credits every 90 days
  • Unlimited objective and AI grading
  • Detailed feedback and complete history
  • 90-day preparation cycle with full Pro access

Recurring subscription. Cancel anytime.

Included in every paid plan

Ten full-length PrepEx DET practice tests

Each test takes about 60 minutes, includes 35 timed tasks across all 13 task families, and ends with a saved 10–160 practice estimate, detailed speaking and writing feedback, and targeted recommendations. See how the ten practice tests work.

View Full Mock Tests Try Free Task Practice
10full-length tests
35timed tasks each
13task families
~60 minper test

One DET Pro entitlement. Three timelines.

Sprint, 30-day, and 90-day members receive the same Pro feature access. Choose only by how long you want to prepare before each renewal.

Ten full-length testsAbout 60 minutes and 35 timed tasks in each test.
Actionable feedbackCriterion-level speaking and writing coaching.
Full learning recordDetailed history, saved progress, and score trends.
Personal directionError patterns, dashboard insights, and recommendations.
Practice quality

DET-style practice built to test real English.

Daria Zhiberina Kate Feng Julian Mendez
Original PrepEx DET-style content
Independent practice, with a documented review standard
PrepEx's wider content team includes language educators, exam specialists, and assessment reviewers.
Meet the PrepEx content team

Useful DET practice needs more than a familiar screen. Prompts must create enough room to show real language ability, objective items need one defensible answer, and speaking and writing feedback must stay tied to evidence in the learner's response.

PrepEx creates independently authored DET-style material. As a Global Partner Network member, our team can consult current DET test-readiness resources when checking format guidance and scoring language. Our content process combines those references with structural, language, fairness, media, answer-key, and rendered-interaction review. Learner prompts and private grading material are kept under separate access rules.

AI may help generate candidates and evaluate practice, but it does not make a draft publishable by itself. PrepEx results are preparation estimates designed to show what to work on next; they are not official Duolingo English Test scores.

13 Current DET task families represented across the practice experience
4 + Grammar Listening, Reading, Writing, Speaking, and language foundations
Original Independently authored DET-style prompts, questions, and response paths
Protected Private answer keys and grading context stay server-side before submission
Common questions

Clear answers before you choose.

Are the ten full-length practice tests included in every paid plan?
Yes. Every paid DET Pro plan includes all ten full-length PrepEx DET practice tests. Each test contains 35 timed tasks across all 13 task families and ends with a saved PrepEx practice estimate and report. Full practice tests are not included in the free task-practice allowance.
Do the 7-day, 30-day, and 90-day plans unlock different features?
No. DET Sprint, DET Pro, and Three-month Pro unlock the same DET Pro features: the full library, unlimited objective grading and AI evaluation, detailed feedback, history, dashboard analysis, error patterns, and recommendations. Petra credits scale with the billing cycle: 1,400 per 7 days, 6,000 per 30 days, or 18,000 per 90 days.
Does the Three-month Pro plan renew?
Yes. It renews every 90 days until canceled. DET Sprint renews every 7 days, and DET Pro renews every 30 days.
Will my existing Founder price change?
No. Existing Founder subscribers keep their original rate while their subscription remains continuously active. If you cancel and subscribe again later, the current public price will apply.
How does DET grading and feedback work?
Objective tasks are graded against protected answer data. Speaking and Writing use AI evaluation tied to the response and task context. Free users receive their saved response, rubric scores, and a concise focus plan; DET Pro adds response-grounded evidence for every criterion, review history, patterns, and recommendations. Every score shown by PrepEx is a practice estimate, not an official DET result.
Who creates and reviews the practice material?
PrepEx independently creates its DET-style content. Global Partner Network resources help our team check current readiness guidance and scoring language, while our publishing standard combines automated validation with language, fairness, media, answer-key, and interaction review. Meet the wider PrepEx content team.
Is DET Pro separate from TOEFL, IELTS, PTE, and CELPIP?
Yes. DET Pro is a product-scoped subscription. A paid plan for another PrepEx exam does not automatically unlock DET Pro, and a DET Pro subscription does not replace your other exam subscriptions.
Can I cancel?
Yes. You can cancel from the Account page. Your access continues through the paid billing period, and the subscription will not renew after that period. Refund requests are handled under the PrepEx Terms of Service and applicable consumer law.

PrepEx is a member of the Duolingo English Test Global Partner Network. Our practice content, feedback, and score estimates are independently created by PrepEx and are not official DET materials, scores, or results. Duolingo English Test is a trademark of Duolingo, Inc.