How to Set Website Time Limits in Firefox

Firefox does not document a built-in per-website minutes-per-day timer. To limit time on YouTube, Reddit, or another site, use a Firefox extension such as Block Site or LeechBlock NG. For children, use Windows Family Safety or macOS Screen Time so the limit applies beyond Firefox. On school or company computers, administrators can deploy Firefox’s WebsiteFilter policy to block URL patterns.

Choose the right control

Need	Best option	What it does	Main limitation
Personal focus sessions	Block Site or LeechBlock NG	Blocks named websites on schedules or during focus periods.	An experienced user can disable the extension; it applies only in Firefox.
Recurring schedule for specific hostnames	Block Site	Supports time/date rules, wildcard or regular-expression matching, and a master password.	It is still a browser extension, not a device-wide control.
One-time 15, 30, or 60-minute block	Website Blocker: MT	Its listing documents those preset durations and custom whole-minute deadlines.	Availability and behavior can change as the listing is updated.
Child safety across apps and browsers	Microsoft Family Safety or macOS Screen Time	Password-protected operating-system controls that Firefox respects.	Configuration happens outside Firefox and usually requires the child to use a managed account.
School or company-managed Firefox	WebsiteFilter policy	Central URL blocking with exception patterns.	The policy documentation describes blocking, not a daily time-quota counter.

Set a recurring limit for one Firefox profile

1. Install an extension from Mozilla Add-ons

1. Open the Firefox application menu.
2. Select Add-ons and themes, then open Extensions.
3. Search for Block Site or LeechBlock NG.
4. Choose the listing published through Mozilla Add-ons and install it.

Mozilla’s family-and-student guidance names both extensions for restricting distracting websites. Review the publisher, permissions, and current listing before installing.

2. Add the sites and schedule

Open the extension’s settings and add each hostname you want to restrict. For example, add youtube.com and www.youtube.com if the extension does not automatically include subdomains. Block Site documents wildcard and regular-expression matching, date rules, time schedules, and a master password.

• Use a recurring window for a daily limit, such as blocking a site during work hours.
• Use date rules for an exam week, holiday, or temporary break.
• Use wildcard patterns when a site uses several subdomains.
• Set the master password before handing the profile to someone else.

3. Test before relying on the rule

1. Create a rule for a harmless site you control or a site you can afford to interrupt.
2. Open a new tab and visit the hostname and a common subdomain.
3. Confirm the block starts and ends at the scheduled times.
4. Test private browsing only if you intend to allow it; extension behavior in private windows depends on the permission you grant.
5. Keep the settings password private and record the schedule somewhere you can update it.

Use a one-time timer

If you need to stop access after one session rather than every day, use an extension whose Mozilla Add-ons listing documents a one-time duration. Website Blocker: MT lists 15-, 30-, and 60-minute blocks plus custom whole-minute deadlines. Install it from Mozilla Add-ons, select the duration, add the target hostname, and verify that the countdown blocks the site when it expires. Because extension availability and interfaces can change, confirm the current listing and test the behavior before using it for an important deadline.

Set limits for children with operating-system controls

Browser extensions are weak parental controls because they can be disabled and do not govern other browsers. Mozilla directs Windows users to Microsoft Family Safety and Mac users to Family Sharing/Screen Time.

Windows

1. Create or select the child’s managed Windows account.
2. Open Microsoft Family Safety and add website or app restrictions for that account.
3. Set the allowed schedule or daily duration and protect the parent settings with your account credentials.
4. Sign in to Firefox as the child and verify that the restriction applies.

macOS

1. Open System Settings and choose Screen Time for the child’s account.
2. Configure App Limits, Downtime, or web-content restrictions as appropriate.
3. Turn on Family Sharing when managing another Apple account.
4. Use a Screen Time passcode that the child does not know, then test Firefox and another browser.

Firefox checks the operating-system parental-control state and enables Prefer:Safe mode while those controls are active. Mozilla says this setting can be turned off only through the password-protected parental settings on the operating system. Device-level controls are preferable when the goal covers more than Firefox.

Block sites on managed computers with WebsiteFilter

Administrators can deploy Firefox’s WebsiteFilter enterprise policy. It accepts URL match patterns, supports exception patterns, and allows up to 1,000 entries in each block or exception array. Use it for centrally managed URL blocking in a school or company environment.

WebsiteFilter is a blocklist policy. The cited administrator documentation does not describe a counter that measures minutes per day, so it cannot by itself implement a documented daily time quota.

Why a limit may not work

Symptom	Likely cause	Fix
The site still opens	The rule matches one hostname but not its subdomain, alternate domain, or redirect target.	Add the required hostnames or use the extension’s documented wildcard matching. Test the final URL after redirects.
The user disables the block	The extension is not a strong security boundary.	Use a master password for personal focus, or move the rule to Family Safety/Screen Time for a child account.
Other browsers remain unrestricted	Firefox extensions run only in Firefox.	Use operating-system parental controls or a managed network/device policy.
Private windows bypass the rule	The extension lacks permission to run in private windows.	Enable private-window access in the extension settings, then retest. Do this only on a profile where that behavior is intended.
The schedule uses the wrong time	The extension or operating system uses a different timezone, or daylight-saving time changed.	Check the computer’s timezone and the extension’s schedule interpretation; test at the next boundary.
A child can change the setting	The restriction is configured only in an extension or the parent account is not protected.	Use a separate child account and a password-protected Family Safety or Screen Time configuration.
A managed policy does not apply	The policy file is malformed, deployed to the wrong profile, or the URL pattern is invalid.	Validate the policy syntax, restart Firefox, and test a simple known URL before adding exceptions.

Reliability and privacy considerations

• Extensions: Fast to install and suitable for personal focus, but they can be disabled by a knowledgeable user and do not control other browsers.
• Operating-system controls: Stronger for children because they cover the device or account and are protected outside Firefox.
• Enterprise policy: Consistent for managed Firefox installations, but it provides URL blocking rather than a documented minutes counter.
• Testing: Check the exact hostname, redirects, private-window behavior, timezone, and another browser when the requirement is device-wide.

Or skip the browser setup

If your goal is to capture a page after changing Firefox settings, ScreenshotNeo provides a website screenshot API at screenshotneo.com. Its capture flow accepts cookie and consent banners, removes more than 60 known consent platforms plus newsletter popups and chat widgets, and lets you turn each cleanup step off. Bot checks, blank pages, timeouts, failed loads, and cache hits are not billed; the response reports the result in X-Page-Verdict and X-Billed headers.

See the ScreenshotNeo API documentation for all options. A basic request is:

curl -G "https://api.screenshotneo.com/v1/shot" -d access_key=YOUR_API_KEY --data-urlencode url=https://stripe.com -o shot.webp

import requests
r = requests.get("https://api.screenshotneo.com/v1/shot", params={"access_key": "YOUR_API_KEY", "url": "https://stripe.com"}, timeout=90)
open("shot.webp", "wb").write(r.content)

const q = new URLSearchParams({ access_key: 'YOUR_API_KEY', url: 'https://stripe.com' });
const res = await fetch(`https://api.screenshotneo.com/v1/shot?${q}`);

ScreenshotNeo also offers an MCP server so Claude, Cursor, and other MCP clients can take screenshots, inspect pages, and capture PDFs. The free plan includes 1,000 screenshots per month with no card; paid plans start at $5 for 3,000. Create a free ScreenshotNeo account.

FAQ

Can Firefox limit YouTube to 30 minutes every day?

Firefox itself does not document a per-site daily quota. Use an extension with a recurring schedule, or configure an operating-system control if the limit must apply across browsers.

Can I block a site after a certain time?

Yes. Block Site documents scheduled time and date rules, and Website Blocker: MT documents one-time duration choices. Test the rule against the exact hostname you need to restrict.

Is an extension enough for parental control?

No. Mozilla notes that extensions can be disabled and do not work in other browsers. Use Microsoft Family Safety or macOS Screen Time for password-protected, device-level enforcement.

Does WebsiteFilter count minutes?

The cited Firefox administrator documentation describes URL block and exception patterns, with up to 1,000 entries in each array. It does not describe a daily time counter.