Firefox Browser Add-ons
  • Extensions
  • Themes
    • for Firefox
    • Dictionaries & Language Packs
    • Other Browser Sites
    • Add-ons for Android
Log in
Preview of ScriptDrag — Third-party Script X-ray

ScriptDrag — Third-party Script X-ray by Vietcodex

See which third-party scripts drag down a page — their size, estimated main-thread cost, and what to defer or drop.

Some features may require paymentSome features may require payment
0 (0 reviews)0 (0 reviews)
Download Firefox and get the extension
Download file

Extension Metadata

Screenshots
About this extension
ScriptDrag x-rays the third-party scripts dragging down any web page — and turns anonymous domains into a ranked, named to-do list. One click, no DevTools.

Third-party JavaScript — tag managers, analytics, chat widgets, ad networks — is where page weight quietly piles up. ScriptDrag reads the page's own performance timing and shows you exactly who is on your page, how heavy each one is, and what to cut first.

WHAT YOU GET

Free
• Who's actually on your page — every third-party script named (Google Tag Manager, Intercom, Doubleclick…) with its category, not anonymous domains.
• A kill-list ranked by impact — third parties sorted by estimated main-thread cost, so you fix the worst offenders from the top.
• Performance budget badge — see at a glance whether the page is lean, getting heavy, or over budget.
• 5 scans per day — no account, no setup.

Pro (one-time $89)
• The full kill-list — every third-party domain, not just the top offenders.
• Redundant-vendor detector — flags when you ship 3 analytics tools or 2 chat widgets, the bloat you can cut today.
• Duplicate-library detection — catches the same library loaded twice from different CDNs.
• CSV / JSON export — take the data into a spreadsheet or a ticket.
• Branded shareable report — one click turns a scan into a client-ready Markdown or printable report with your own name on it.

HONEST BY DESIGN
ScriptDrag reads the page's own Resource Timing — no profiling trace, no Lighthouse run, no setup. The main-thread cost is an estimate (~1 ms per KB of JavaScript) and is labeled as such. Scripts that hide their size (no Timing-Allow-Origin header) are shown as “size hidden”, never as 0. Vendor names come from the open third-party-web dataset, bundled locally.

PRIVATE BY DESIGN
Runs only when you click the icon. The page is analyzed locally on your device and never leaves your browser; nothing is sent to us.

HOW IT WORKS
1. Open the page you want to audit and let it load.
2. Click the ScriptDrag icon.
3. Work the kill-list top-down — defer, lazy-load, or drop the heaviest third parties.

PRICING
Free — 5 scans per day with named vendors, the kill-list, and the budget badge.
Pro — one-time $89, no subscription. Unlimited scans, the full kill-list, the redundant-vendor detector, CSV/JSON export, and the branded shareable report.

Built by Vietcodex.
Rated 0 by 0 reviewers
Log in to rate this extension
There are no ratings yet

Star rating saved

5
0
4
0
3
0
2
0
1
0
No reviews yet
Permissions and data

Data collection:

  • The developer says this extension doesn't require data collection.
Learn more
More information
Add-on Links
  • Homepage
  • Support site
  • Support Email
  • Copy add-on ID
Version
0.1.0
Size
104.63 KB
Last updated
4 days ago (Jul 14, 2026)
Related Categories
  • Web Development
License
All Rights Reserved
Version History
  • See all versions
Add to collection
Report this add-on
Go to Mozilla's homepage

Add-ons

  • About
  • Firefox Add-ons Blog
  • Extension Workshop
  • Developer Hub
  • Developer Policies
  • Community Blog
  • Forum
  • Report a bug
  • Review Guide

Download

  • Download Firefox
  • Windows
  • macOS
  • iOS
  • Android
  • Linux
  • All

Latest Builds

  • Nightly
  • Beta

Firefox for Business

  • Enterprise

Community

  • Connect
  • Contribute
  • Developer

Follow

  • Instagram
  • YouTube
  • TikTok
  • Bluesky
  • Podcast
  • Privacy
  • Cookies
  • Legal

Except where otherwise noted, content on this site is licensed under the Creative Commons Attribution Share-Alike License v3.0 or any later version.