For martial arts and dance schools

Know who's ready before grading day.

Obi keeps your roster, your syllabus and your class register in one place, and tells you exactly which students have earned their next belt.

Open Obi See how it works

Free. Runs in your browser. Your data never leaves your device.

Grading week, the old way.

Re-read the syllabus. Count the register by hand. Try to remember which techniques each student has already shown you. Someone gets missed, and the certificate still has to be typed up. Obi does the counting, so you can do the teaching.

Three things, then the app does the rest.

  1. Set your ladder once.

    Rename the eight seeded belts or build your own. For each belt, list the techniques it needs, a minimum number of classes and a minimum time in the belt before it.

  2. Tick the register and sign off techniques.

    Pick the date, tick who's on the mat. When a student shows you a technique, tick it on their page. The date is recorded for you.

  3. Promote and print.

    Obi flags every student who has met every requirement. Promote them on grading day and print the certificate, or print a progress sheet any time to show a parent exactly where their child stands.

Three requirements. One answer.

For every student, Obi checks the next belt's techniques, the classes attended since their last promotion, and the days they have held their current belt. When all three are met, the badge turns green. When they are not, it tells you precisely what remains.

An instructor can still promote early. Obi warns, it never blocks.

Requirements for Blue

  • Techniques: 3 of 4
  • Classes: 34 of 36
  • Days in belt: 138 of 150
In progress Ready 2 more classes · 1 technique to tick · 12 more days All requirements met. Ready to grade.

Everything a grading needs, nothing a school doesn't.

  • A roster that answers the question.

    Every student with their belt and status at a glance. Search by name, filter to Ready, and see the ready-to-grade count in the header.

  • A curriculum you own.

    Rename belts, pick their colours, reorder them, add and remove techniques. Dance school? Call them Grade 1 to Grade 8. Obi won't let you delete a belt a student still holds.

  • A register that takes a minute.

    Pick the date, tick who's present, done. Made for a phone on the mat, with a bottom tab bar and big tap targets.

  • Techniques, signed off with dates.

    Tick a technique when you see it. Obi keeps the date so the progress sheet shows exactly when each one was passed.

  • Certificates and progress sheets.

    One landscape certificate per promotion, one portrait progress sheet per student, both with your school and your name. Print from the browser.

  • Your data stays yours.

    No accounts, no servers. Everything lives in your browser. Export a JSON backup to move computers, import it to restore, reset to start over.

Light and dark follow your system. Works on a laptop at the desk and a phone on the mat.

Try it right here.

This is the real app, running in this page. It starts with the seeded eight-belt ladder and no students. Add one, tick a class, and it saves in your browser.

Open full screen
  • One school, one browser. Obi stores everything in this browser's local storage. Clear the browser and you clear the data, so export a backup now and then.
  • Moving computers? Settings has Export and Import. The backup is one JSON file.
  • Printing Obi uses your browser's print dialog. Certificates print landscape, progress sheets print portrait.

Grading day is coming. Know who's ready.

Open Obi, add your first student and tick today's class. Everything else follows.

Open Obi

No sign-up. Nothing to install.