Miseba — Find stream highlights from the chat.

Miseba is a Chrome extension for editors who create clips from YouTube live-stream archives. Mark highlights right on the watch page, analyze chat activity, and export them in a format your editing software can use directly.

Features

Free

Mark highlights (in point, out point, notes)
Export text for YouTube chapters

Pro (monthly)

Chat activity analysis and heatmap display
Jump to chat search results
Export in CSV / EDL / FCPXML formats (for editing software)

Pricing

980 JPY / month (Pro plan). This is an auto-renewing subscription and you can cancel anytime. Cancel from the extension panel or popup under "Manage subscription". Free features are available without a subscription.

Getting started

Install Miseba from the Chrome Web Store.
Open a YouTube watch page (https://www.youtube.com/watch*) and the panel appears on screen.
To use Pro features, sign up for the monthly plan from "Upgrade" in the panel or popup.

Billing and subscription

Pro billing is a monthly auto-renewing subscription processed through the payment provider ExtensionPay (via Stripe). This extension has no payment server of its own and does not store or collect payment information such as card numbers. After cancellation, auto-renewal stops at the end of the current billing period.

Privacy Policy

Last updated: 2026-06-28

Overview

Miseba ("this extension") is designed with user privacy as the top priority. This extension does not collect, transmit, or share your browsing content, highlight data, or settings. The only exception is the Pro purchase process, where payment information such as your email address is sent to the payment provider ExtensionPay / Stripe (details below).

Information we store

This extension only stores, on your device, the following information that you create or configure in the browser.

Highlight data (in/out point times, notes, linked video ID) — IndexedDB
Settings (export fps, custom dictionary for chat search) — chrome.storage
Billing status cache (whether you have Pro) — stored in chrome.storage by ExtensionPay

This data is stored locally in your browser and is never sent outside your device (except for billing-status checks). This extension has no external server of its own.

About chat analysis

To build the activity heatmap, this extension reads the public chat replay of the video being played from YouTube, and aggregates message counts and density over time on your device. Chat message text is never transmitted, permanently stored, or redistributed externally. The aggregated result (the heatmap) is handled in memory only; the only data saved is the highlights you create.

Information we do not collect

Browsing history / search history
Location / contacts
Payment information such as card numbers (payments are processed by ExtensionPay / Stripe; this extension does not store or collect card data)

This extension contains no analytics, tracking, or advertising mechanisms.

About Pro billing

Paid (Pro) features are billed through the payment provider ExtensionPay (via Stripe). This extension has no payment server of its own.

During checkout, your email address and payment details are sent to ExtensionPay / Stripe and handled under their respective privacy policies.
The only thing this extension receives and stores from these services is whether you have paid or not; it never receives payment information such as card numbers.
To detect completed payments (onPaid), messages are exchanged on https://extensionpay.com/*.

About video content

This extension only moves the playback position and displays the heatmap; it does not download, store, or redistribute video, audio, or chat.

Permissions

The main features of this extension only run on YouTube watch pages (https://www.youtube.com/watch*). Reading chat also only communicates with the same origin (youtube.com). In addition, a content script runs on https://extensionpay.com/* to sync Pro billing status, and a background service worker manages the billing state. This is used only to detect completed payments and retrieve billing status via ExtensionPay, and it does not access any other pages or data.

Deleting your data

Saved highlights can be deleted from this extension's panel. You can also delete them at any time by clearing the browser's site data for YouTube, or by removing the extension.

Changes to this policy

If this policy is updated, the "Last updated" date on this page will be revised.

Contact

For questions about this extension, please use the developer contact / support section on this extension's Chrome Web Store listing page.