Grammarly vs BAND9AI for IELTS Writing: Grammar Polish vs Rubric Scoring

Rubric depth · GRA traps · May 2026

Direct answer

Grammarly fixes surface errors; BAND9AI scores whether your essay answers the prompt under IELTS descriptors. Grammar checkers make essays read cleaner—but they do not fix weak Task Response, broken paragraph logic, or off-topic rewrites. BAND9AI targets TR/TA, CC, LR, and GRA on real IELTS task types so you see why an essay is capped before you pay exam fees—not just that it reads grammatically.

Core difference: error highlights vs examiner logic

Students often polish a Band 6 essay into “Band 6.5 English” while the position and structure stay weak—see hidden Band 6 ceiling in Writing.

Grammarly Grammar, clarity, and tone—not IELTS rubrics
BAND9AI Task-type prompts, criterion scores, calibrated checks
Shared risk Suggestions that drift off-prompt or sound over-formal

Side-by-side on IELTS Writing

DimensionGrammarlyBAND9AI
Task ResponseNot evaluated—may change your argumentFlags missed prompt parts and weak positions
CoherenceNo paragraph-level logic scoreCC feedback on progression and referencing
Lexical resourceWord-choice hints—not collocation fitFlags over-formal or unnatural word choice
Band predictionNoneCalibrated reality checks

When to use each tool

Use Grammarly for one or two sentences after rubric feedback—never whole-essay blind rewrites. Use BAND9AI for timed Task 2 on fresh prompts and when template patterns might hide weak logic. Compare QuillBot vs BAND9AI and ProWritingAid vs BAND9AI.

Key takeaways

  • Grammar polish is not the same as Task Response or coherence improvement.
  • Grammarly can push tone toward unnatural formality under LR scrutiny.
  • BAND9AI shows descriptor-level leaks on fresh prompts.
  • Edit surface errors only after rubric feedback—not instead of it.

FAQ

It can reduce GRA errors—but grammar polish alone does not fix Task Response or coherence gaps examiners penalise.
Tone and clarity suggestions can drift off-prompt or sound unnatural under Lexical Resource scrutiny. Use targeted edits only.
Yes: BAND9AI first on a fresh draft; Grammarly last for specific sentences you already understand.

Score against IELTS descriptors—not grammar highlights alone.

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