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Browser Extensions · head to head

FireMonkey vs Night Eye

FireMonkey logo

FireMonkey

Browser Extensions

User scripts and user styles in one Firefox extension

From
Free
Rated
-
Full reviewWebsite
Night Eye logo

Night Eye

Browser Extensions

Dark mode on any website

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: FireMonkey firefox only, and requires a recent one: version 93 on desktop, 113 on Android.; Night Eye can impact browser performance, especially on older or less powerful devices due to color conversion processing
  • They diverge on capability: FireMonkey covers Scripts and styles together, Night Eye covers Dark mode.
  • Prices and features above were last checked on 15 September 2026.

Where they differ

Only the attributes on which FireMonkey and Night Eye actually diverge.

Attributes where FireMonkey and Night Eye differ
AttributeFireMonkeyNight Eye
Pricing modelopen-sourceUnknown
PlatformsFirefoxChrome, Safari, Edge, Firefox, Opera, Brave
FoundedUnknown2018

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Browser Extensions).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in FireMonkey

  • Scripts and styles together
  • Monaco editor with ESLint
  • Unlimited client-side storage
  • Global injection
  • Notifications and clipboard
  • Firefox for Android

Only in Night Eye

  • Dark mode
  • Color analysis
  • Image preservation
  • Per-site settings
  • Chrome support
  • Firefox support
  • Edge support
  • Safari support

What people use each for

The jobs each tool is most often brought in to do.

FireMonkey

  • Running user scripts and user styles without two separate extensionsnot Night Eye
  • Restyling sites with CSS alongside scripted behaviour changesnot Night Eye
  • Editing scripts in a full editor inside the browsernot Night Eye
  • Injecting CSS globally across every sitenot Night Eye
  • Managing a mixed library of scripts and styles from one dashboardnot Night Eye

Night Eye

  • Force a consistent dark mode on websites that don't natively support onenot FireMonkey
  • Reduce eye strain and blue light exposure during night browsing via a built-in blue-light filternot FireMonkey
  • Per-site color, brightness, contrast, and saturation customizationnot FireMonkey
  • Selectively convert only icons/small images rather than full images to preserve visual fidelity in dark modenot FireMonkey

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

FireMonkey

  • Firefox only, and requires a recent one: version 93 on desktop, 113 on Android.
  • Not a drop-in replacement for Greasemonkey, Tampermonkey or Stylus. The project says so itself, so an existing library may need adjusting.
  • A much smaller user base than Tampermonkey or Violentmonkey, which means fewer people have hit the bug you are about to hit.
  • No Chrome, Edge or Safari build, so it cannot be the answer for anyone working across browsers.
  • Combining scripts and styles in one extension also combines the blast radius: one extension with permission to inject both into every page.

Night Eye

  • Can impact browser performance, especially on older or less powerful devices due to color conversion processing
  • Ineffective on web applications with fixed color schemes that cannot be altered
  • Does not work offline or on non-web content
  • Limited customization on websites that have their own built-in dark mode implementation

Pricing, plan by plan

FireMonkey

Free
  • Open sourceFree
    • MPL-2.0 licensed
    • Unlimited scripts and styles
    • No account required

Night Eye

Free
  • LiteFree
    • Dark mode on up to 5 websites
    • No ads
  • Pro$9/year
    • Up to 3 browsers
  • Pro Max$14/year
    • Up to 6 browsers
  • Lifetime$40/mo
    • Unlimited browsers
    • Lifetime updates

Which should you pick?

Choose FireMonkey if

  • You need scripts and styles together.
  • You want to start without paying.
  • You work on Firefox.
  • You also want monaco editor with eslint.
FireMonkey review

Choose Night Eye if

  • You need dark mode.
  • You want to start without paying.
  • You work on Chrome, Safari, Edge, Firefox, Opera, Brave.
  • You also want color analysis.
Night Eye review

Questions people ask

Is FireMonkey or Night Eye better?
Neither clearly leads. FireMonkey starts at Free and Night Eye at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, FireMonkey or Night Eye?
FireMonkey starts at Free and Night Eye at Free.
Does FireMonkey or Night Eye run on more platforms?
FireMonkey runs on Firefox. Night Eye runs on Chrome, Safari, Edge, Firefox, Opera, Brave.
Can I use FireMonkey for free?
Both have a free tier, so you can try either at no cost before committing.
What is FireMonkey best used for?
FireMonkey is most often used for running user scripts and user styles without two separate extensions, restyling sites with css alongside scripted behaviour changes, editing scripts in a full editor inside the browser, injecting css globally across every site. Of those, running user scripts and user styles without two separate extensions and restyling sites with css alongside scripted behaviour changes are not what Night Eye is typically brought in for.
What can FireMonkey do that Night Eye cannot?
FireMonkey covers Scripts and styles together, Monaco editor with ESLint, Unlimited client-side storage, Global injection. Night Eye covers Dark mode, Color analysis, Image preservation, Per-site settings.

Answered from the vendors’ own pages

FireMonkey: What makes FireMonkey different from Violentmonkey?

It manages user styles as well as user scripts. The usual arrangement is a script manager plus a separate style manager such as Stylus; FireMonkey replaces both with one extension.

Source
Night Eye: What is Night Eye?

Night Eye is a browser extension that applies dark mode to websites by analyzing page colors and converting them into a comfortable dark theme. It preserves photos and videos and offers customization options for brightness, contrast, and blue light filtering.

Source
FireMonkey: Which browsers does FireMonkey support?

Firefox only. Desktop requires Firefox 93 or later and Android requires 113, with an API minimum of 102.

Source
Night Eye: What is the pricing for Night Eye?

Night Eye Lite is free with dark mode on up to 5 websites. Night Eye Pro costs $9/year for up to 3 browsers, Night Eye Pro Max costs $14/year for up to 6 browsers, and lifetime updates cost $40 for unlimited use across 10 browsers.

Source
FireMonkey: Is FireMonkey open source?

Yes, under the MPL-2.0 licence.

Source
Night Eye: Which browsers does Night Eye support?

Night Eye is available for Chrome, Safari, Microsoft Edge, Firefox, Opera, Brave, and other Chromium-based browsers.

Source
FireMonkey: Will my existing Tampermonkey scripts work?

Not necessarily. The project states that while it shares functionality with Greasemonkey, Tampermonkey and Stylus, there are differences, so scripts and styles written for those may need adjusting.

Source
Night Eye: Does Night Eye track my browsing?

No. Night Eye does not monitor, process, or store browsing activity. Webpage conversion is performed locally on the user's device. No ads appear in the free Lite version.

Source
FireMonkey: What editor does FireMonkey use?

Current versions use the Monaco editor with ESLint, the same editor component that powers VS Code.

Source
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