Code Watermark Injector

Inject unique watermarks into your source code to track ownership, trace leaks, and prove authorship. Each copy gets a unique structural signature based on a recipient ID — all free, private, and no signup required.

Inject unique watermarks into your source code to track ownership and trace leaks. Each watermarking technique produces functionally identical code with a unique structural signature tied to a recipient ID.

Code Language

Recipient ID

Shuffle Seed

Watermarking Techniques

Source Code

function calculateTotal(prices, taxRate) {
  const subtotal = prices.reduce((sum, price) => sum + price, 0);
  const tax = subtotal * taxRate;
  const total = subtotal + tax;
  return { subtotal, tax, total };
}

function formatCurrency(amount, locale = 'en-US') {
  return new Intl.NumberFormat(locale, {
    style: 'currency',
    currency: 'USD',
  }).format(amount);
}

const config = {
  apiUrl: 'https://api.example.com',
  timeout: 5000,
  retries: 3,
  debug: false,
};

const SUPPORTED_LOCALES = ['en-US', 'en-GB', 'de-DE', 'ja-JP'];
const MAX_RETRIES = 5;
const DEFAULT_TIMEOUT = 10000;

class OrderProcessor {
  constructor(apiKey) {
    this.apiKey = apiKey;
    this.orders = [];
  }

async processOrder(orderData) {
    const validated = this.validate(orderData);
    if (!validated) return null;
    this.orders.push(orderData);
    return this.submit(orderData);
  }

validate(orderData) {
    return orderData.items && orderData.items.length > 0;
  }

async submit(orderData) {
    return { status: 'submitted', id: Date.now() };
  }
}

export { calculateTotal, formatCurrency, config, OrderProcessor };

Paste your source code above, set a recipient ID, and click Apply Watermark to inject unique structural watermarks.

Each recipient gets code with a unique combination of declaration ordering, comment markers, variable name suffixes, and property ordering.

Privacy Guarantee

All watermark injection runs entirely in your browser. Your code and recipient IDs never leave your device — no uploads, no API calls, no tracking.

Unique Code Fingerprinting

Each watermarked copy receives a unique structural signature based on a recipient ID. The same source code watermarked for different recipients produces functionally identical code with distinct declaration ordering, variable names, and comment markers.

Declaration Reordering

Deterministically shuffle function declarations, variable declarations, class methods, and import statements using a seed-based algorithm. Each recipient gets a unique declaration order that preserves all code semantics.

Recipient-Specific Names

Append a recipient-based suffix to variable, function, and class names. The suffix is derived from the recipient ID, making watermarked copies traceable back to their source through identifier inspection.

Stealth Comment Injection

Inject unique comment markers with recipient IDs, timestamps, and hash checksums at strategic positions throughout the code. Multiple comment styles are used to avoid detection by automated stripping tools.

Leak Tracing & Forensics

Watermark code distributed to different clients or employees with unique recipient IDs. When a leak occurs, examine the leaked code to identify which recipient was the source by checking declaration order, variable name suffixes, and embedded comment markers.

Proving Code Ownership

Inject watermarks into your proprietary code before sharing it with third parties. The unique structural signature provides evidence of ownership and can be used to prove that code originated from your organization.

Demo/Trial Code Tracking

Distribute watermarked demo or trial versions of your software to potential customers. Each trial copy carries a unique identifier that can be traced back if the code is shared or leaked publicly.

Enterprise Source Control

Large enterprises distributing code to multiple teams or contractors can watermark each distribution. This provides accountability and helps identify the source of unauthorized code sharing.

Open Source Contribution Tracking

When contributing to open source projects that require attribution tracking, watermarked code can help verify the provenance of contributions and detect unauthorized use of contributed code.

Code Review Attribution

During code reviews, watermarked code helps reviewers understand which version or recipient generated specific code changes. The unique patterns make it easy to identify the source of reviewed code.

What Is Code Watermarking?

Code watermarking embeds unique, invisible identifiers into source code without changing its behavior. Unlike encryption or obfuscation which aim to hide code, watermarking aims to make each distributed copy uniquely identifiable. Techniques include reordering declarations, inserting unique comments, renaming variables with recipient-specific suffixes, and applying deterministic whitespace patterns.

How Does Deterministic Shuffling Work?

The tool uses a seed-based deterministic shuffle algorithm. The seed value combined with the recipient ID produces a predictable but unique ordering of declarations. This means the same recipient ID always produces the same watermark, making verification consistent. Different recipient IDs produce different orderings, allowing each distributed copy to be uniquely identified.

Are Watermarked Copies Detectable?

Watermarked code is functionally identical to the original. The changes are structural — declaration order, variable names, comment presence, and property ordering. An automated tool could potentially detect differences by comparing two copies, but without access to the original or another watermarked copy, the watermark is invisible to casual inspection.

Combining with Other Protections

Watermarking works well alongside other protection techniques. You can obfuscate code after watermarking to protect the logic, but be aware that minification and variable renaming may obscure some watermark indicators. For best results, maintain a mapping of original watermarked copies alongside any obfuscated distribution versions.

What is code watermarking?

Code watermarking embeds unique identifiers into source code without changing its functionality. Each watermarked copy carries a unique structural signature — such as declaration ordering, variable names, and comment markers — that can be traced back to the recipient.

How does the declaration reordering work?

The tool uses a seed-based deterministic shuffle algorithm. The seed and recipient ID together produce a predictable ordering of function declarations, variable declarations, and class methods. The same recipient ID always produces the same ordering, making verification consistent across copies.

Will watermarked code still work the same?

Yes. Watermarking only changes structural aspects of the code — the order of declarations, variable names, comments, and whitespace. The logic and behavior remain identical. JavaScript and CSS are both resilient to these structural changes.

Can watermarks be detected or removed?

Watermarks are designed to be invisible during normal use. An automated tool comparing two differently watermarked copies could detect differences. Variable name suffixes and unique comments can be stripped by minifiers, while declaration reordering is more resilient. For maximum traceability, use multiple techniques together.

What is the recipient ID used for?

The recipient ID is used to generate unique watermark patterns. Different recipient IDs produce different declaration orderings, variable name suffixes, comment markers, and whitespace patterns. When a leak occurs, the recipient ID can be determined by analyzing the watermarked code.

What does the shuffle seed do?

The seed controls the deterministic randomization of declaration ordering. Combined with the recipient ID, it ensures that each recipient gets a unique but consistent ordering. Using the same seed and recipient ID always produces the same result, allowing reproducible watermarks.

Does this work with minified or obfuscated code?

Watermarking is best applied to readable source code before minification or obfuscation. If you apply obfuscation after watermarking, some indicators (like variable names and comments) may be stripped. Declaration reordering is more resilient and can survive basic minification.

Can I watermark CSS code?

Yes. The tool supports CSS watermarking through property reordering — CSS rule declarations are sorted alphabetically differently per recipient. Comment markers and whitespace patterns can also be applied to CSS code.

Is my data safe when using this tool?

Yes — 100% safe. All watermark injection runs entirely in your browser. Your source code and recipient IDs never leave your device and are never uploaded to any server.