Edexia vs CoGrader
Both tools use AI to grade essays. The difference is who they were built for. Edexia is purpose-built for IB English and Australian senior-secondary curricula (VCE, HSC, QCE, WACE, SACE, TASC, BSSS, NTCET). CoGrader serves US classrooms with state-test and AP rubrics. If you teach outside the US, this comparison should make the choice straightforward.
| Feature | Edexia | CoGrader |
|---|---|---|
| Primary market | IB & senior-secondary English (all eight Australian curricula) | US K-12 state tests & AP |
| How it works | Uses assessment, rubric, curriculum, and school context | Pre-built rubric templates |
| Published accuracy | 81.2% exact match, 98.3% within one band (579 essays) | Not published |
| Moderation tools | Blind grading, department-level calibration | Individual teacher focus |
| AI detection | Built-in writing replay with keystroke analysis | Not included |
| LMS integration | On roadmap | Google Classroom, Canvas, Schoology |
| Handwriting support | Scan and transcribe handwritten scripts | Not included |
| Data hosting | Australian servers, ST4S assessed | US servers |
| Pricing | Free for teachers and students | Free tier (100 essays/mo), then $15-19/mo |
| Scale | 40+ schools across AU, NZ, and international IB | 50,000+ teachers, 1,000+ US schools |
The core distinction
CoGrader is a mature product with strong LMS integrations and a large US user base. It supports 30+ state-test and AP rubrics, and if you teach in a US school that runs Google Classroom or Canvas, it plugs in with very little friction. That is its strength.
Edexia does not try to cover every curriculum. It goes deep on the ones it supports: IB English, VCE, HSC, QCE, WACE, SACE, TASC, BSSS and NTCET. The AI uses each curriculum’s official rubrics, knows the prescribed texts, and applies the relevant assessment context. The result is 81.2% exact-match accuracy and 98.3% within one mark band, validated across 579 real essays at St Bernard’s College.
CoGrader has not published equivalent accuracy data.
Contextual, not template-bound
CoGrader works from pre-built rubric templates. You pick a rubric, paste the essay, and get a grade. Edexia takes a different approach: it applies the assessment, rubric, curriculum, and school-specific context when generating feedback. Edexia does not use user data to train or fine-tune AI models.
This matters most at the department level. When a faculty uses Edexia for moderation, it surfaces where markers disagree so the team can calibrate together. Blind grading and department-level tools are built in.
AI detection
Edexia includes writing replay: the full keystroke history of every submission, showing exactly how a student composed their essay. Pauses, edits, copy-paste events, and composition patterns are all visible. Teachers can see whether a student wrote the essay themselves without relying on a probabilistic detector.
CoGrader does not include AI detection.
Handwriting
IB and Australian exams are still written by hand. Edexia has built-in OCR for handwritten scripts, including the crossings-out, insertions, and margin notes that trip up general transcription tools. CoGrader is designed for typed submissions.
Data and privacy
Edexia hosts student data on Australian servers and is assessed under ST4S. Student work is siloed by school and never shared across institutions. CoGrader stores data on US servers.
For Australian and international schools with strict data residency requirements, this is often the deciding factor.
Pricing
Edexia is free for every teacher and student. CoGrader offers a free tier of 100 essays per month, then charges $15-19 per month.
When CoGrader is the better fit
If you teach in a US school, use Google Classroom or Canvas, and need state-test or AP rubric alignment, CoGrader is purpose-built for that workflow. Its LMS integrations are mature and its US user base is large. Edexia does not currently offer LMS integrations, though they are on the roadmap.
When Edexia is the better fit
If you teach IB English, VCE, HSC, QCE, WACE, SACE, TASC, BSSS or NTCET and want grading that is calibrated to your specific curriculum, Edexia is the only tool built for that. It applies curriculum-aligned assessment context, handles handwritten scripts, includes AI detection, and keeps student data in Australia.
The best way to decide is to test both on your own essays. Edexia is free to try. See Edexia for IB English, Edexia for VCE English, Edexia for HSC English, Edexia for QCE English, or Edexia for WACE English for curriculum-specific details.