Automatically stopping browser media when a user falls asleep or reaches a chosen time limit. It is catalogued under Video & media players on PulseGate.

Who should use SleepyFox?

SleepyFox is a consumer product built for firefox users who listen to or watch media before sleeping.

Yes — SleepyFox is free to use.

What platforms does SleepyFox run on?

SleepyFox runs on the web and embeddable surfaces.

Is SleepyFox still maintained?

Unverified. SleepyFox has not been re-checked since it entered the index, so there is no finding either way — and only a positive finding would say otherwise.

Who develops SleepyFox?

SleepyFox is developed by ZHENHUI ZHOU.

When did SleepyFox launch?

SleepyFox first shipped in 2025.

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SleepyFox

Name: SleepyFox
Author: ZHENHUI ZHOU

mozilla.orgVideo & media players

SleepyFox is a Firefox browser extension that pauses media automatically when a configured sleep timer expires. It supports Firefox on desktop and Android and uses browser permissions to control tabs and media playback.

FreeWebEmbeddableCloud-managed

Visit mozilla.org

Overview

5 features

SleepyFox sits in PulseGate's Video & media players category. Automatically stopping browser media when a user falls asleep or reaches a chosen time limit. SleepyFox is a consumer product aimed at firefox users who listen to or watch media before sleeping. It is available for free. It runs on the web and embeddable surfaces.

Behind SleepyFox is ZHENHUI ZHOU, and it first shipped in 2025. Among its 5 catalogued features are Sleep Timer, Media Pausing, and Browser Tab Access. The interface is available in 32 languages, including Czech, German, and Greek.

Summary written by a language model from the project’s public pages.

Sleep Timer
Media Pausing
Browser Tab Access
Notifications
Firefox Android Support

Built with & integrations

Runs on

BrowserEmbeddableCloud-managed

Trust & compliance

Verified signals

HTTPSPrivacy Policy Terms of ServiceFree tierMulti-languageStore-verified publisher

Legal

Indexing history

What PulseGate has recorded for this listing

Indexed9 Sept · 11:35 UTC
SleepyFox verified via Firefox Add-ons
Source: Firefox Add-ons · Open

Frequently asked questions about SleepyFox

What is SleepyFox?: Automatically stopping browser media when a user falls asleep or reaches a chosen time limit. It is catalogued under Video & media players on PulseGate.
Who should use SleepyFox?: SleepyFox is a consumer product built for firefox users who listen to or watch media before sleeping.
Is SleepyFox free?: Yes — SleepyFox is free to use.
What platforms does SleepyFox run on?: SleepyFox runs on the web and embeddable surfaces.
Is SleepyFox still maintained?: Unverified. SleepyFox has not been re-checked since it entered the index, so there is no finding either way — and only a positive finding would say otherwise.
Who develops SleepyFox?: SleepyFox is developed by ZHENHUI ZHOU.
When did SleepyFox launch?: SleepyFox first shipped in 2025.
What languages does SleepyFox support?: The interface is available in 32 languages, including Czech, German, and Greek.

At a glance

Pricing: Free
Platforms: Web
Built for: Firefox users who listen to or watch media before sleeping
Model: B2C
Solves: Automatically stopping browser media when a user falls asleep or reaches a chosen time limit.

Registered as

Firefox Add-ons: sleepyfox

Developer

ZHENHUI ZHOU

Index record

Indexed: 9 Sept 2026
Lifecycle: Alive
Last seen: 9 Sept 2026

Identity audit (13)

Slug: sleepyfox-mozilla-org
Lifecycle state recorded: 9 Sept 2026
Verification state: Indexed for public listing
Listing state: Listed: yes
Index status: Included in index
Latest evidence snapshot: 9 Sept 2026
Timeline basis: Indexed-at chronology. This listing's first-seen date was written by the catalog backfill, not observed here, so it is not treated as a sighting.
Name from: Derived from the project's own page and URL.
Category from: Assigned by a language model.
Summary from: Written by a language model from public pages.
Languages from: Detected by a language model, checked against the page's own declaration.
Last updated: 9 Sept 2026
Canonical URL: https://addons.mozilla.org/en-US/firefox/addon/sleepyfox

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