GradeBlaster connects to Canvas LMS and uses AI vision to analyze student submissions, generate detailed feedback, and post grades automatically — so you can focus on teaching.
30-day free trial · No credit card required · macOS 11+
Built for Canvas instructors at
GradeBlaster handles the entire grading pipeline — from pulling submissions out of Canvas to posting final grades back — with AI doing the heavy lifting.
Grade your entire class in one click. AI downloads all submissions, analyzes each one against your rubric, generates written feedback, and posts grades to Canvas automatically. Zero babysitting required.
AI vision examines submission images for design quality, centering, labels, proportions, and any visual criteria you define in your rubric.
Checks file structure, layer naming, color usage, and technical requirements — all configurable per assignment type.
Create reusable rubric templates with Visual and Technical criteria, custom weights, and feedback comment templates. Build once, use forever.
Connects directly to Canvas LMS via API. Pulls assignment submissions, reads student rosters, and posts grades and comments back automatically.
Every grade comes with a detailed, criterion-by-criterion comment posted directly to Canvas. Students get real feedback, not just a number.
Grade first, publish when ready. Post grades in draft mode so students can't see them until you've reviewed and approved the batch.
Track every grading session. View class averages, grade distributions, and export full history to CSV for your records.
Real-time token usage and cost tracking per session. Know exactly what each grading run costs down to the cent.
Use Anthropic Claude or OpenAI GPT-4o as your AI backend. Bring your own API key — no markup, no middleman.
Paste in the assignment brief and AI checks if students actually followed the requirements — not just whether it looks good.
Prefer to review before posting? Grade one student at a time with AI suggestions, then confirm, override, or skip each grade.
Paste your Canvas URL and an API access token. GradeBlaster connects instantly and lists all your courses and assignments.
Select a grading profile (or create one in minutes) and pick the assignment. GradeBlaster fetches all submissions automatically.
Hit Blast All. AI downloads each file, runs visual and technical analysis against your criteria, calculates scores, and writes personalized feedback for every student.
Scores and detailed comments are posted directly to Canvas — live for students to see, or in draft mode for your review first. Done.
Most AI grading tools make you click through one student at a time. GradeBlaster's Blast All mode runs the entire class in one background job — you hit go, make a coffee, and come back to a finished gradebook.
"I used to spend a full Sunday grading fashion flats. Now I run Blast All on Friday afternoon and I'm done by the time the coffee finishes brewing. This tool pays for itself the first week."
"The grading profiles are genius. I built one for each type of assignment — sketches, flats, technical specs — and just pick the right one. The AI suggestions are surprisingly accurate."
"What really sold me is the feedback quality. Students get detailed, criterion-by-criterion comments explaining their deductions. Much better than what I'd write when I'm on student #25 at midnight."
Start free. Pay when you're convinced.
No credit card required
Instant license key · Renews annually
For departments & teams
Download GradeBlaster and get 30 days of full access free. No credit card, no account required.
Yes. GradeBlaster works with any Canvas LMS instance — self-hosted or Instructure-hosted. You just need an API access token from your Canvas account settings and instructor-level access to the course you want to grade.
Yes — GradeBlaster uses your own API key (Anthropic or OpenAI), so you're billed directly by them. This keeps costs transparent and low. Grading a class of 30 students typically costs $0.25–$1.00 in AI tokens depending on your model — there's no markup or middleman.
GradeBlaster works with PDFs and image files (PNG, JPG, etc.). It converts PDF pages to images for visual analysis. This makes it ideal for design portfolios, sketches, technical drawings, illustrations, and any file-based assignment type.
Accuracy depends heavily on your grading criteria. Well-defined, objective criteria (label placement, centering, file naming) produce highly consistent results. Subjective criteria (aesthetic quality, creativity) should be reviewed with the step-by-step mode, where you can accept or override AI suggestions. Many instructors use Blast All for a fast first pass, then spot-check outliers.
GradeBlaster runs entirely on your Mac. Submission files are downloaded to your local machine and never uploaded to our servers. The only external calls are to the Canvas API (your institution) and your chosen AI provider. Your Canvas token and AI key are stored locally in a config file on your Mac and never leave your machine.
Yes. Use Draft Mode to post grades with the assignment muted — Canvas will store the grades but students won't see them until you unmute the assignment. You can also use Local Mode to run AI analysis and review grades without posting anything to Canvas at all.
After 30 days, GradeBlaster will redirect to the license page and require a valid license key to continue. Your grading history, profiles, and settings are all preserved. Purchase a Pro License ($99/year) and enter the key to resume immediately.
Currently, GradeBlaster ships as a native macOS app (macOS 11+, Intel and Apple Silicon). Windows and Linux support is on the roadmap. If you'd like to be notified when Windows is available, reach out at support@gradeblaster.com.
Join instructors who've reclaimed their time with AI-powered grading. 30-day free trial, no credit card required.