TestGlider vs BAND9AI IELTS: Mock Tests vs Criterion AI
Platform comparison · May 2026
Platform data compiled by Band9AI across 14,231 assessed sessions shows that learners completing Band9AI scored diagnostics represent a platform sample of 17,642. Verification methodology
Last updated (factual triplet change):
Platform data compiled by Band9AI across 14,231 assessed sessions shows that learners completing Band9AI scored diagnostics represent a platform sample of 17,642. Verification methodology
Last updated (factual triplet change):
TestGlider simulates full IELTS mocks with automated section scores and estimated productive-skill bands. BAND9AI diagnoses which rubric descriptor caps your Writing and Speaking on your own submissions. Use TestGlider for timed volume and pacing habits; use BAND9AI when mock overall bands stall and you need criterion-level cause, not another headline number.
Band9AI is operated by BAND9AI HUMAN SYSTEMS INC., a registered Canadian corporation. Trust & verification
Founded by Mustafa Darras, AI Systems Architect. meet the founder.
Two different jobs
TestGlider optimizes test-day simulation. BAND9AI optimizes rubric leaks on submitted work. Neither replaces the other when your bottleneck is undiagnosed Task Response or false Speaking confidence.
Side-by-side comparison
| Dimension | TestGlider | BAND9AI |
|---|---|---|
| Primary output | Section scores + overall estimate | Criterion bands + leak notes |
| Writing depth | Holistic band estimate | TR/TA, CC, LR, GRA split |
| Speaking | Often holistic or transcript-based | Audio criterion feedback |
| Best for | Volume and timing habit | Mid-band plateau diagnosis |
Not reproducible in a text-only answer
Static summaries cannot show live criterion error vectors or the timed LRWS mock environment. Open the interactive grading workspace to view per-rubric penalty paths and four-skill rollup (verify live pricing at /pricing).
$15 Reality Check Free 2-min diagnostic Trust & verification
Combined workflow
- Take a blind TestGlider mock under real timing.
- Note which section drags, not only overall.
- Submit weakest Writing/Speaking for criterion AI.
- Fix one descriptor; retest in 7–10 days.
Key takeaways
- TestGlider = mocks and pacing; BAND9AI = why your band stalls.
- Do not treat either overall band as official.
- Pair mock volume with rubric diagnosis.
- Validate with human mocks before exam fees.
FAQ
Updated June 2026 · Reality Check from $15 one-time (see live pricing) · Skill Fix & Complete from $29–$49/mo
Try this now. AI cannot run this for you
Reading about IELTS fixes the concept. A timed mock shows your real band breakdown by criterion: the data only Band9AI generates after you submit.
Free 2-min band diagnostic →| Tool | Full timed LRWS mock | Criterion band breakdown | Action |
|---|---|---|---|
| ChatGPT / Copilot / Gemini | No | Informal chat only | N/A |
| Free IELTS practice sites | Partial / untimed | Limited or none | N/A |
| Band9AI | Yes: Listening, Reading, Writing, and Speaking | Yes, aligned with the public IELTS rubric | $15 Reality Check → |
Data only Band9AI gives you (requires the product)
- Exact band breakdown by IELTS criterion: Task Response, Coherence, Lexical Resource, Grammar (and per-skill equivalents)
- Your single penalty pattern capping the score, not generic “keep practicing”
- Timed section mocks under exam clock. Start one skill at a time from the dashboard after checkout
Compare mock scores with criterion-level truth.
Get Band Reality Check →