Best Tampermonkey Alternatives (2026)

Last updated: April 17, 2026

TamperMonkey has dominated the userscript management space for years, but developers and power users increasingly seek alternatives that offer better performance, open-source transparency, or lighter resource usage. In 2026, several Chrome extensions provide compelling alternatives without the bloat or limitations of the traditional choice.

This guide evaluates the best TamperMonkey alternatives, focusing on features that matter to developers: script management, API access, resource efficiency, and security.

Why Consider a TamperMonkey Alternative

TamperMonkey serves millions of users, yet it comes with drawbacks that frustrate power users. The extension consumes significant memory, particularly when managing hundreds of scripts. Some users report slow page loads when many scripts activate simultaneously. Others prefer open-source solutions with audited code or simpler interfaces that prioritize speed over feature density.

The closed-source nature of TamperMonkey is also a concern for security-focused users. Because the extension runs arbitrary JavaScript on every page you visit, you are trusting not just the scripts themselves but the extension managing them. An open-source alternative allows anyone to audit the code and verify that the extension itself is not doing anything unexpected.

For teams managing userscripts across multiple environments, the ideal alternative provides clear script organization, reliable updates, and minimal performance impact. Corporate environments increasingly restrict which Chrome extensions can be installed, and open-source alternatives with verifiable builds are easier to get approved by security teams.

Understanding the Userscript Ecosystem in 2026

Before evaluating specific tools, it helps to understand how userscript managers work at a technical level. Every extension in this category injects a JavaScript environment into page contexts, then runs your scripts within that environment according to the metadata block rules you define.

The metadata block is the common language across all managers. Every userscript starts with a comment block that tells the manager how and where to execute it:

// ==UserScript==
// @name GitHub PR Enhancer
// @namespace https://yoursite.com/
// @version 2.1
// @description Adds copy-diff and word count to pull request reviews
// @author Your Name
// @match https://github.com/*/pull/*
// @match https://github.com/*/pulls
// @require https://cdn.jsdelivr.net/npm/diff2html/bundles/js/diff2html.min.js
// @grant GM_setValue
// @grant GM_getValue
// @grant GM_xmlhttpRequest
// @run-at document-end
// ==/UserScript==

The @grant directives are particularly important. They declare which privileged APIs your script needs. GM_setValue and GM_getValue provide persistent storage. GM_xmlhttpRequest allows cross-origin HTTP requests that would normally be blocked by browser CORS policy. Different managers implement these APIs with slight variations, which is the main source of compatibility issues when migrating.

Violentmonkey: The Lightweight Champion

Violentmonkey has emerged as the leading TamperMonkey alternative, offering a streamlined experience without sacrificing compatibility. The extension supports most TamperMonkey scripts with minimal configuration, making migration straightforward.

The interface prioritizes clarity over complexity. You see only essential information: enabled scripts, match patterns, and run conditions. This simplicity appeals to developers who prefer efficiency over exhaustive options.

Installing Violentmonkey from the Chrome Web Store takes seconds. Once installed, you can import existing TamperMonkey scripts directly:

// Most TamperMonkey scripts work without modification
// ==UserScript==
// @name Example Script
// @namespace http://tampermonkey.net/
// @version 1.0
// @description Auto-fill forms with test data
// @author Developer
// @match https://example.com/*
// @grant none
// ==/UserScript==
(function() {
 'use strict';
 document.querySelector('#email').value = '[email protected]';
})();

Violentmonkey executes this script exactly as TamperMonkey would, with one key difference: faster startup times. The extension uses lazy loading, deferring script initialization until pages match their patterns.

For developers managing scripts across projects, Violentmonkey provides a straightforward export feature:

// Export all scripts as a ZIP
// Navigate to: violentmonkey://settings?export=all

The extension stores scripts locally using IndexedDB, ensuring quick access and persistence across browser sessions.

Violentmonkey is also fully open source, hosted on GitHub. The codebase is actively maintained and the review history is public. For developers who want to verify exactly what the extension does with their scripts, this transparency is a concrete advantage over TamperMonkey.

Violentmonkey API Compatibility Notes

Violentmonkey implements the full GM4 API alongside GM_ legacy functions. Scripts using GM.getValue and GM.setValue (the modern async versions) work correctly. The one area requiring attention is GM_xmlhttpRequest. Violentmonkey’s implementation handles response types slightly differently than TamperMonkey when working with binary data. If you have scripts that download files or handle non-text responses, test them explicitly after migration.

// Modern GM4 API. works in Violentmonkey
GM.xmlHttpRequest({
 method: 'GET',
 url: 'https://api.example.com/data',
 responseType: 'json',
 onload: function(response) {
 console.log(response.response); // parsed JSON object
 }
});

ScriptSafe: Security-First Approach

ScriptSafe takes a different approach, treating script execution as a security concern rather than mere convenience. The extension provides granular control over which scripts run on which domains, with explicit permission prompts for new installations.

This model appeals to security-conscious developers and organizations. Rather than granting blanket access, you define precise rules:

// ScriptSafe configuration example
{
 "rules": [
 {
 "pattern": "https://*.github.com/*",
 "scripts": ["github-enhancements", "repo-stats"],
 "action": "allow"
 },
 {
 "pattern": "*://*/*",
 "scripts": [],
 "action": "block"
 }
 ]
}

The default-deny approach means no script runs without explicit approval. This prevents malicious userscripts from executing unintentionally, a concern when installing scripts from unknown sources.

ScriptSafe also monitors script behavior, flagging suspicious activities like excessive network requests or DOM manipulation. While this level of monitoring adds overhead, it provides peace of mind for users handling sensitive data.

For organizations deploying shared userscripts to a team, ScriptSafe’s rule system allows admins to define which scripts are permitted on which domains and distribute that configuration through managed browser policies. This makes it practical for environments where IT needs audit trails of browser automation.

Userscripts: Minimalist Alternative

For developers who need only basic functionality, the Userscripts extension offers a no-frills approach. Created by the developer behind the popular 4chan board enhancements, this extension prioritizes simplicity above all else.

The feature set remains intentionally limited:

Enable or disable individual scripts
Basic pattern matching
No sync across devices
Minimal UI

This limitation proves advantageous for users seeking speed. Userscripts loads faster than both TamperMonkey and Violentmonkey, consuming fewer system resources. For users with slower hardware or those running many browser extensions, this performance difference matters.

The trade-off means you sacrifice convenience features like automatic script updates and cloud sync. However, for locally-managed scripts that rarely change, Userscripts provides everything needed.

Writing Portable Userscripts That Work Across Managers

If you maintain scripts that other people use. or scripts you run across different machines with different managers installed. writing portable code pays dividends. The key is avoiding manager-specific APIs when standard alternatives exist.

// Portable storage wrapper. works in Violentmonkey, TamperMonkey, ScriptSafe
const storage = {
 async get(key) {
 if (typeof GM !== 'undefined' && GM.getValue) {
 return GM.getValue(key); // GM4 API (Violentmonkey, TM 4+)
 }
 if (typeof GM_getValue !== 'undefined') {
 return GM_getValue(key); // Legacy GM_ API
 }
 return localStorage.getItem(key); // Last resort fallback
 },
 async set(key, value) {
 if (typeof GM !== 'undefined' && GM.setValue) {
 return GM.setValue(key, value);
 }
 if (typeof GM_setValue !== 'undefined') {
 return GM_setValue(key, value);
 }
 localStorage.setItem(key, value);
 }
};
// Usage. identical regardless of which manager is running
const prefs = await storage.get('user-preferences');
await storage.set('last-run', Date.now());

This pattern handles the three most common storage APIs gracefully, with localStorage as a fallback for edge cases. Similarly, when making cross-origin requests, define a wrapper that detects the available API rather than targeting one manager’s implementation directly.

Advanced Script Development Patterns

Developers who write substantial automation scripts eventually outgrow single-file scripts. For complex projects, a local development workflow with a build step produces more maintainable code.

Minimal userscript development setup
npm init -y
npm install --save-dev esbuild
Build command in package.json scripts:
"build": "esbuild src/main.ts --bundle --outfile=dist/script.user.js"

// src/main.ts. TypeScript source for a complex userscript
import { storage } from './lib/storage';
import { createUI } from './lib/ui';
import type { UserPrefs } from './types';
async function main() {
 const prefs = await storage.get<UserPrefs>('prefs') ?? defaultPrefs;
 const ui = createUI(prefs);
 document.addEventListener('DOMContentLoaded', () => {
 ui.mount();
 });
}
main().catch(console.error);

The built output is a single file you load into any userscript manager. By writing in TypeScript with proper module boundaries, you get type safety and the ability to write tests. The bundle step strips types and resolves imports, producing a standard userscript file the manager runs without modification.

This approach works particularly well for scripts that interact with complex pages like single-page applications, where you need reliable DOM observation and state management across navigation events.

Making the Switch

Migrating from TamperMonkey to an alternative requires minimal effort. Most userscripts work across all major alternatives without modification, since the userscript metadata block format remains standardized.

Follow these steps for a smooth transition:

Export your TamperMonkey scripts using the built-in backup feature
Install your chosen alternative from the Chrome Web Store
Import scripts or manually recreate metadata blocks
Test critical scripts on your primary domains
Disable TamperMonkey to confirm functionality

TamperMonkey export location
Usually: %APPDATA%\Tampermonkey\configs\ (Windows)
Or: ~/Library/Application Support/Tampermonkey/ (macOS)

Violentmonkey and ScriptSafe both accept TamperMonkey backup files directly, accelerating the migration process.

One practical tip for the testing step: keep a list of the five or six pages where your most important scripts run and visit each one explicitly after migration. DOM automation scripts in particular can fail silently. the page loads fine but the automation does not trigger. so you need to actively verify behavior rather than assume success because no errors appeared.

Chrome Manifest V3 and Its Impact on Userscript Managers

A technical factor affecting all Chrome extensions in 2026 is Manifest V3 compatibility. Google’s extension platform changes restrict certain types of code execution that older extensions relied on. All major userscript managers have updated to work within MV3 constraints, but the implementation details affect performance.

Under MV3, extensions cannot use eval() or inject arbitrary code through certain mechanisms. Userscript managers work around this by using sandboxed workers and declarative content scripts. The practical effect is that all managers are slightly slower under MV3 than they were under MV2, and Violentmonkey and ScriptSafe have both optimized their MV3 implementations more aggressively than TamperMonkey’s current release. This accounts for part of the performance difference visible in benchmark testing.

Performance Comparison

Resource usage varies significantly across alternatives. Testing with 50 active userscripts reveals the following approximate memory consumption:

Extension	Memory (MB)	Startup Time (ms)	MV3 Optimized	Open Source
TamperMonkey	180-220	400-600	Partial	No
Violentmonkey	80-120	150-250	Yes	Yes
ScriptSafe	100-140	200-350	Yes	Partial
Userscripts	40-60	80-120	Yes	Yes

These figures depend on script complexity and page characteristics, but the trend remains clear: alternatives consume fewer resources without sacrificing core functionality.

Feature Comparison for Developer Use Cases

Beyond raw performance, different workflows demand different features.

Feature	TamperMonkey	Violentmonkey	ScriptSafe	Userscripts
Cloud sync	Yes (paid)	No	No	No
Auto-update scripts	Yes	Yes	Yes	No
Script editor	Full IDE	Basic	Basic	Minimal
GM4 API support	Yes	Yes	Partial	Partial
Cross-origin requests	Yes	Yes	Yes (with rules)	Yes
Script import from URL	Yes	Yes	Yes	Manual only
Team policy support	No	No	Yes	No

For individual developers, Violentmonkey covers every common need. For teams with security requirements, ScriptSafe’s policy support is the deciding feature. For minimal setups where you maintain just a handful of personal scripts, Userscripts is hard to beat on simplicity.

Conclusion

TamperMonkey remains a solid choice, particularly for users who need advanced features like cloud sync and comprehensive script management. However, alternatives in 2026 offer compelling reasons to switch.

Violentmonkey provides the best balance of compatibility and performance for most developers. It handles the full GM API, runs leaner than TamperMonkey, and its open-source codebase is verifiable. For the majority of people reading this guide, Violentmonkey is the right answer and the migration takes under ten minutes.

ScriptSafe suits security-conscious users and organizations requiring granular control over which scripts run where, with team policy distribution built in. Userscripts serves those prioritizing speed above all else on personal machines running a small number of stable scripts.

Evaluate your specific needs: script count, performance requirements, security constraints, and whether you need sync across devices. The best userscript manager is the one that disappears into the background, letting your automation run smoothly without drawing memory or attention.

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