Account

Limits to know when using Bút Nghiên

A summary of the numbers you'll often run into: file upload sizes, OTP codes, password length, exam time limits and number of attempts.

Published August 29, 2026 · Last updated October 15, 2026

Steps

  1. Before uploading a file, check the maximum size for that type of file in the table below.
  2. When you create an exam, check that the time limit and number of attempts are within the allowed range.
  3. If a file is too large: compress the images, split it into several smaller files or save it in a more compact format, then upload it again.

Options and limits

Avatar
PNG or JPEG image, up to 2MB.
Assignment files
Up to 15MB per file, for both student submissions and teacher attachments.
Importing an exam from a file
Word (.docx), Excel (.xlsx) or a text-based PDF, up to 20MB, uploaded on the “Upload exam document” page.
Uploading files in the advanced editor
Word (.docx) or Excel (.xlsx), up to 10MB. PDF isn't accepted here.
Student lists
CSV file up to 2MB and 200 students per import.
Password
From 8 to 100 characters.
Email OTP code
6 digits. After each send, you have to wait 60 seconds before you can send it again.
Exam time limit
From 1 to 1440 minutes (24 hours) when you create an exam or change its settings. When you generate an exam from a blueprint: from 1 to 360 minutes.
Number of attempts
In step 1 of the exam builder: 1–10 attempts, 1 by default. In step “3. Exam room settings” and the exam's “Settings” box: 1–20 attempts.
Points per question
In the exam builder: from 0.25 to 10 points, in steps of 0.25, 1 point by default.
Assignment maximum score
From 1 to 100 points.
  • Bút Nghiên can't read text inside images: scanned PDFs or image-only PDFs can't be imported. Use a PDF with selectable text, or a Word/Excel file.
  • The create exam page has no AI feature for writing exams automatically.

Related articles

← All guides