For individual submissions
Starter
€9.00
one-time · no subscription
8corrections
with your selection
€1.13 equivalent per correction
24 red pens · credits do not expire
51 more red pens needed for your stack
For teachers · no student accounts or class lists
Correct student writing from a photo. Your judgment stays central.
No student accounts or class lists to set up: take a photo of the page, let Tuba mark handwritten or typed work against your rubric and review the correction.
No credit card · 12 free red pens · up to 2 pages per base correction · no subscription
See pack prices and cost per correctionInside a correction
English · short narrative
Understand the changes
Last summer we gowent1 to the lake. My brother swimswam2 every day.
Past Simple · 1, 2
“Last summer” places the story in the past. In affirmative past-simple sentences, “go” becomes “went” and “swim” becomes “swam”.
You review the suggestions and decide the assessment.
How it works
Three steps, fewer clicks.
- 01
Prepare your photo
Photograph handwritten or typed pages. Remove names and personal details before uploading. Tuba reads the pages as one connected piece of work.
- 02
Add context
Pick grade level, modules and rubric criteria — or stick with the defaults.
- 03
Keep what fits
Transcription, marking, feedback, points — side by side. You decide what makes it into the grade. Tuba never grades without you.
Clear costs · no subscription
Your stack. Your choice of pack.
Plan in submissions, not credits. Choose your correction options and see which pack covers your next stack.
12 free red pens: four base corrections with up to two pages each. No credit card.
75 red pens for 25 submissions · 3 each
Standard covers your stack: €24.00
Fits your stack
Standard
€24.00
one-time · no subscription
30corrections
with your selection
€0.80 equivalent per correction
90 red pens · credits do not expire
15 red pens left after your stack
For regular corrections
Bulk
€69.00
one-time · no subscription
100corrections
with your selection
€0.69 equivalent per correction
300 red pens · credits do not expire
225 red pens left after your stack
How pages, modules and leftover credits work
The first 2 pages are included. Each extra page costs 1 red pen and each optional module 1 red pen. You buy a whole pack; unit prices are rounded credit-use equivalents.
The estimate starts without an existing balance or free credits. It highlights the cheapest single pack that covers the stack; pack combinations are not compared. This calculator plans your usage; the app processes submissions individually.
Every pack is for one account. “Bulk” is a volume pack and does not include access for a staff team.
Full pricing detailsWhat stays, even when the AI gets it wrong
You stay the teacher. Tuba just suggests.
No student accounts or class lists
You only need your teacher account. Remove names before uploading; Tuba does not automatically anonymize images.
Privacy in detail →No subscription, no surprises
Buy red pens once; they never expire. If an analysis fails, you get them back automatically.
Suggestion, not verdict
The AI sometimes gets things wrong, even on correctly spelled words. Every marking comes with a reason; you decide what to use.
AI correction for school and teaching
Correct texts with AI: take a photo, read the result.
- 01
AI writing correction for teachers
Built for teachers, but useful for other texts too: Tuba marks photographed essays and assignments with markings and explanations.
- 02
From handwriting to feedback
Simply take a photo. Tuba transcribes handwriting and print before correction, feedback and rubric-based grading are created.
- 03
From photo to PDF correction
Phone photo instead of retyping: read several pages, review marked corrections and export the final PDF.
FAQ
Quick answers first.
Are uploaded submissions automatically anonymous?
No. Remove names and personal details before uploading. Tuba does not require student accounts or class lists, but it does not automatically anonymize images. The text itself can also identify someone.
Do I need a credit card to try it?
12 red pens come free with your account, no payment details required. Buy packs only when you run out.
What does a single correction cost?
A base correction (2 pages, with error analysis) costs 3 red pens; a full correction with every module (feedback, grading, evaluation) costs 6 red pens. The Standard pack (€24) includes 90 red pens — that is 15 full corrections or 30 base corrections, roughly €0.80 per base correction. The Bulk pack (€69) brings it down to around €0.69 per base correction.
Does AI decide the grade?
No. Tuba provides suggestions: transcription, markings with reasons, feedback, and optional points against your rubric. You set the grade. The results view and PDF export contain the AI output; make your own changes outside Tuba.
Does it work with handwritten student work?
Yes. Tuba reads handwritten and typed text from phone photos. Good lighting and a flat angle noticeably improve accuracy.
Where is my data stored?
App data is hosted in the EU. Images and texts are sent to Anthropic for AI analysis, which may involve processing in the USA, with retention of up to 30 days as described in our privacy policy. Saved corrections can be deleted in your account. See our privacy and processor pages for details.
Is there a subscription?
No. You buy red pens once and they never expire. If an analysis fails, they flow back automatically.