User JavaScript and CSS

Enhance your browsing with User JavaScript and CSS extension. Inject custom scripts and styles effortlessly on any website, boosting productivity with FlashID integration.

Seamless Custom Script Injection

Unlock the power of personalization! Inject your own JavaScript or CSS on any site instantly, with features like URL masking and custom libraries for ultimate flexibility.

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Seamless Custom Script Injection

User JavaScript and CSS is a versatile Chrome extension for injecting custom JavaScript and CSS rules into any webpage. Integrated with FlashID, it empowers users to customize their browsing experience effortlessly.

Instant Script Execution

Execute custom JavaScript and CSS rules immediately on any webpage, supporting userscripts and userstyles with high performance.

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Instant Script Execution

Custom Libraries & URL Masking

Include your own libraries and use URL masking to apply scripts across multiple pages efficiently, streamlining your workflow.

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Custom Libraries & URL Masking

Secure & Private Customization

Operate in a secure environment with FlashID, ensuring privacy while enhancing sites with live CSS, iframe support, and MV3 compatibility.

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Secure & Private Customization
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Unlimited Multiplicity

Multiple devices, no limits
No purchase limit, no multiplicity limit, no opening limit

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Multi-Platform Control

Anytime, anywhere, just click
No client download required, accessible via PC and mobile browsers

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Application Management

Application management so easy
Bulk install, uninstall, and launch applications

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RPA

Leverage FlashID’s pre-built RPA templates for fast automation or custom workflows in secure cloud.

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API

FlashID API handles account lifecycles and automates browser actions: batch social logins.

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One-Click Sharing

Efficient management
Join a team with one click, share cloud devices among multiple users

Client Success Stories Trusted Worldwide

  • David Lee
    David Lee

    Operations Manager, Efficiency Experts

    “User JavaScript and CSS has revolutionized how we customize web pages. Instant execution and URL masking save us hours daily.”
  • Sarah Johnson
    Sarah Johnson

    Digital Marketing Manager, Tech Innovations

    “With this extension, managing userscripts across sites is seamless. FlashID integration makes it even better for our team.”
  • Alex Smith
    Alex Smith

    Customer Support Lead, Service Plus

    “Injecting custom CSS and JS has streamlined our testing. Features like custom libs are invaluable for developers.”

Customize Any Website Effortlessly

User JavaScript and CSS enables instant injection of scripts and styles, perfect for developers and power users seeking full control over web experiences.

Customize Any Website Effortlessly

Common related content QA

Can User JavaScript and CSS inject scripts on any site?

Yes, it allows injecting custom JavaScript and CSS on any website, with instant execution and URL matching.

Is User JavaScript and CSS safe with FlashID?

Absolutely. FlashID ensures secure, private operations with no data storage.

How does script injection work?

It uses advanced MV3 architecture for high-performance injection, supporting iframes, live CSS, and custom libraries.

Can I use it without interruptions?

Yes! It integrates seamlessly, running scripts instantly upon page load.

Is User JavaScript and CSS compatible with all browsers?

Optimized for Google Chrome. Other browser support is planned.

How do I install the User JavaScript and CSS extension?

Install directly from the Chrome Web Store or via the provided link.

Does FlashID support Firefox extensions?

Currently Chrome-focused, with future Firefox compatibility in consideration.

What if the extension isn't working?

Update to the latest version (3.1.0), clear cache, and restart your browser.

Does User JavaScript and CSS store my data?

No, it prioritizes privacy with local rule management only.

Can I customize settings?

Yes, offers extensive options like URL masking, themes, and injection modes.

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