For individual submissions
For teachers · no student accounts or class lists
Correct student writing from a photo. Your judgment stays central.
Upload a photo: Tuba reads the handwriting, corrects it in red and explains every change. Tap a correction and the spot lights up in the photo. You set the grade.
No credit card · no subscription · 2 pages per correction included · packs from €9
- No AI training on your uploads
- Photos aren't stored permanently
- Tuba stores corrections in the EU
English · grade 7 · 1 page
My summer holidays
My summer holidays
Last summer we go to the lake with
my family. My brother swim every
day and I read three books. One day
it was raining, so we stay in the
house and played cards. It was the
best holyday ever!
Spot 1 of 4 go went
Transcription · recognized text
Last summer we to the lake with my family. My brother every day and I read three books. One day it was raining, so we in the house and played cards. It was the best ever!
Compare anything unusual with the photo before you correct.
Correction · follow the changes
Last summer we to the lake with my family. My brother every day and I read three books. One day it was raining, so we in the house and played cards. It was the best ever!
Tense · 1
“Last summer” sets the story in the past: past simple “went”.
Tense · 2
Irregular verb in the past simple.
Tense · 3
Regular verb: past simple with -ed.
Spelling · 4
Spelling: “holiday”.
Error analysis · 4 spots
Feedback
What worked well
- Clear timeline from the summer to the outlook.
- Vivid details: the rainy day, cards, books.
Work on this
- Past simple of irregular verbs: went, swam.
- Spelling: holiday.
You review the suggestions. The grade stays with you.
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, correction, error analysis, feedback, grading — in tabs, with the photo alongside. Hover over a correction and Tuba shows you the spot in the handwriting. You decide what makes it into the grade.
Tuba in one minute
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
All prices are final prices in EUR. As a small business under § 6(1)(27) of the Austrian VAT Act, we do not charge VAT.
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.
Do I need to remove names before uploading?
Yes. Tuba needs no student accounts or class lists, but it does not anonymize photos automatically. Cover names and personal details before you take the photo – the text itself can also identify someone.
Is an AI trained on my students' work?
No. Tuba uses Claude by Anthropic via the API; under Anthropic's terms this data is not used for training. Anthropic usually deletes it within 30 days (exception: review of possible usage-policy violations). Tuba does not store original photos permanently – they stay in your browser only while the result is open. The transcription and result stay in your account until you delete them.
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 (up to 2 pages, with error analysis) costs 3 red pens; a full correction with every module (feedback, rubric assessment, 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. Tap a correction and Tuba marks roughly where it sits in the photo, so you can quickly tell whether a word was misread. Good lighting and a flat angle noticeably improve accuracy.
Does Tuba work for German and other languages?
Yes. Tuba transcribes and corrects in the language the work is written in – for example English or German. You get feedback and evaluation in English or German. For other languages, check the quality with the free corrections. Tuba is built for texts; it does not reliably assess calculations or formulas.
Where is my data stored?
Your account and saved corrections are stored in the EU (Frankfurt); Tuba does not store original photos permanently. Images and texts are sent to Anthropic for AI analysis, which may involve processing in the USA, usually kept for 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.