How it works
From no AI account at all to a CSV of grades in about ten minutes.
The five steps
Get an API key (free with Gemini)
On the Grade page, step 3, choose "I need a key". The walkthrough takes you to Google AI Studio, where any Google account gets a free key with no card. Paste it back into OpenGrader. Tick "Remember this key on this device" if it is your own computer so you do not retype it, and leave it unticked on a shared one.
Add your rubric
Paste it in, or upload a .txt, .docx, or .pdf. One line per criterion works best. OpenGrader scores against exactly the criteria you give it and does not add its own.
Pick the writing type
This adds genre checks like counterargument handling or textual citation. It is extra feedback only and never changes your rubric score.
Add the class set
Drop one file per student, or paste a single submission with a name. Names come from the filenames, so fix any that look off before you grade.
Grade, review, export
Press Grade. Rows fill in as they finish. Every score and comment is editable. When you are happy, download a CSV, send it to a Google Sheet in your own Drive, or copy a feedback report for a Google Doc.
Questions
Does this cost anything?
OpenGrader is free. You pay only for the AI usage on your own key. A Gemini key is free within a generous limit. A class set on Claude or GPT runs a few cents.
Where does the student writing go?
It is read in your browser and sent straight to the AI provider you picked, using your key. It is never stored on our servers, logged, or kept. Close the tab and it is gone.
A row failed. What now?
The rest of the class keeps grading. When the pass finishes, the failed row shows a Retry button. Most failures are a bad key or a provider rate limit, so wait a moment and retry.
Can I trust the grades?
Treat them as a fast first pass. Every score points back to a line from the student’s own writing, so a bad call is quick to spot. You review and adjust before anything leaves the page.