Quizmark for YouTube™ Add to Chrome

Remember what you learn on YouTube.

Quizmark pauses long videos at natural breaks, asks a few questions about what you just watched, and shows you the exact moment each answer came from.

Add to Chrome, it’s free Watch the 90-second demo

No account. Works with your own AI key or a model on your computer.

A lecturer at a chalkboard with Git snapshots, blobs and a commit graph drawn on it.
15:29 / 1:09:32 Data model, as pseudocode

Quiz 1 of 4

Introduction → Data model, as pseudocode

How Git represents snapshots of code as trees and blobs, and how commits form a history graph.

Questions
3
Difficulty
Medium
Covers
0:00–15:28
Try it. These are real questions Quizmark generated for MIT’s lecture on Git.

One hour of video, four short pauses.

Any YouTube video, divided the way you want.

  1. 0:00

    Watch as usual.

    Questions are written in the background from the video’s captions, before you reach them.

  2. 15:28

    Pause at a natural break.

    Quizmark waits for a chapter change or a pause in speech, then asks only about the stretch you just watched.

  3. 2:32

    Check the source.

    Not sure? Watch button replays the passage behind the question, then brings you back. Your place is kept.

  4. End

    Finish with a final test.

    Before the video ends, one last quiz brings back questions from the whole thing.

Answering beats rewatching.

62%average score on a test the next day, for students who answered four quick questions during an online lecture

54%average score for students who reviewed the same material instead

703 university and community-college students. The study tested in-lecture quizzes in general, not Quizmark. Chan et al., Communications Psychology, 2025

Free. You bring the AI.

There’s no Quizmark account or subscription. Questions are written by a model you choose.

Your own API key

Paste a key from Anthropic, OpenAI, Google Gemini, OpenRouter, xAI, DeepSeek or Moonshot. Your provider bills you directly for what you use.

Fast. Nothing to install.

A model on your computer

Connect a model running in LM Studio or Ollama. Nothing leaves your computer and there’s no bill.

Slower. Needs a capable machine.

Read the privacy policy

Questions

Which videos does it work on?

Any YouTube video with captions, including auto-generated ones: lectures, tutorials, talks, interviews, explainers. Quizmark reads the captions and never downloads the video or its audio, so a video without captions isn’t supported.

How often will it interrupt me?

About every 15 minutes by default, and you can choose anything from 5 to 45. Or turn pauses off and open a quiz from its mark on the timeline whenever you like.

What does it cost?

Quizmark is free. With an API key, your provider charges for usage, separately from any ChatGPT or Claude subscription. A local model costs nothing to run. Quizzes are saved, so rewatching or retaking one never costs twice.

What if a question is wrong?

Every question is checked against the video before you see it, but AI still makes mistakes. Press Watch to hear the passage yourself, and report the question from its answer screen.

Which browsers are supported?

Chrome today. Firefox and Safari versions are in progress.

How is it different from other YouTube quiz tools?

Quizmark waits for natural breaks instead of a fixed timer, checks each question against the video, and links every answer to the moment it comes from. See the comparison.

Try it on the next video you watch.

Add to Chrome, it’s free

Firefox and Safari coming soon.