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# What can you do with substitution rules?

## Summary
Substitution rules in Clonable let you automatically replace specific text, HTML, or images on your cloned website. This is useful when you want to adjust translations, fix wording, change branding, or modify small elements without editing your original site.

With substitution rules, you define what Clonable should look for and what it should replace it with. This article explains the different types of substitution rules, when to use them, and how to set them up correctly.

|| Requirements: You need access to a clone and permission to manage substitution rules


## FAQ

**What is a substitution rule?**  
A rule that tells Clonable to replace specific content with something else on your clone.

**Does this change my original website?**  
No. Substitution rules only affect the clone.

**Can I use substitution rules for full sentences?**  
Yes, but they work best for specific and clearly identifiable fragments.



⏱️ **Reading time:** 6–9 minutes


## What are substitution rules?

Substitution rules allow you to define:

* An **Original** value (what Clonable should look for)
* A **Replacement** value (what it should become instead)

When Clonable finds the original content on your cloned website, it automatically replaces it with your defined replacement.

This gives you precise control over:

* Text fragments  
* HTML elements  
* Images  
* Links  
* Structured content  

All without touching your original website.

To use substitutions properly, it is important to understand how they work. The most important thing to know is that all rules are applied simultaneously. This may sound confusing, so we'd like to explain it to you using an animation. While evaluating rules, the following rules are used to choose between two conflicting rules:
* If rule a has more characters matched than rule b, then rule a takes precedence over rule b.
* When two rules have the same number of characters matched, the rule higher in the table wins.
Below is an animation in which five (overlapping) rules are applied to a piece of source code. In this animation, the words *hit* and *miss* are used to indicate whether or not a rule can match a character. To the right of the rule, you can see how many characters a rule has already matched.

In the animation, you can see that a conflict first arises between the lines `bookcase` and `book`. In this case, both rules have matched 4 characters and therefore the order is considered. Because `bookcase` is above `book`, the entire match of `book` is rejected and nothing is done with this rule. A moment later, a conflict arises between the rules `cabinet` and `bookcase`. Both rules have a full match. Because in this case `bookshelf` has matched more characters than `book` this rule wins and the rule `bookshelf` will be applied. After one rule is applied, all other rules will be reset and all must start over.

### The saving behaviour
Saving substitution rules works in a separate way due to technical reasons. If you add a new substitution rule and then save, all the old substitution rules will first be deleted, and added again. So suppose you have 3 substitution rules, and you add 2 more and then save, 3 rules will first be deleted, and then 5 new ones will be added. This is mainly important to know about the [next trap](https://kb.clonable.net/en/customize/substitution-rules/#errors-in-substitution-rules).

![](https://storage.crisp.chat/users/helpdesk/website/-/4/1/5/7/415740f4b2c87400/matching-10c8529301ce09349add9_sdloud.gif)




## Where to find substitution rules

To manage substitution rules:

1. Open your clone in the Clonable control panel  
2. Go to **Customize**  
3. Click **Substitution rules**

Here you can create, edit, or remove rules.

<<[Substitution rules overview screen]>>



## Types of substitution rules

Clonable supports different types of substitutions depending on what you want to change.



### Text replacements

Use text replacement rules when:

* A translation is incorrect
* A brand name should stay unchanged
* A specific phrase should be rewritten
* A recurring word needs to be adjusted

#### Example

Original:  
Summer sale

Replacement:  
Winter promotion

Every time “Summer sale” appears on the clone, it will be replaced.

| Tip: Be as specific as possible to avoid replacing unintended text.



### HTML substitutions

HTML substitutions allow you to replace or remove specific HTML snippets.

This is useful when you want to:

* Remove buttons or icons  
* Replace banners  
* Modify small layout elements  
* Change links or attributes  

You must copy the exact HTML from the page source, not from developer tools.

||| Technical note: Small differences in spacing or line breaks can prevent a match. Always use the exact snippet from the page source.

If you want to remove something completely, leave the replacement field empty.



### Image replacements

Image substitution rules allow you to swap one image for another.

This is useful for:

* Region-specific banners  
* Localized promotions  
* Different product visuals per market  

You simply replace the original image URL with the new image URL.

Make sure the new image is publicly accessible.



### Using regular expressions (Advanced)

Regular expressions allow flexible pattern matching.

Use this only if you:

* Understand pattern matching  
* Need dynamic replacements  
* Want to match variable content  

||| Technical note: Incorrect regular expressions can break content. Use carefully.

For most users, standard text or HTML replacements are enough.



## How to create a substitution rule

Follow these steps:

1. Open your clone  
2. Go to **Substitution rules**  
3. Click **Add new rule**  
4. Enter the **Original** content  
5. Enter the **Replacement** content  
6. Configure options if needed  
7. Save the rule  

After saving, the rule applies automatically to your clone.

![](https://storage.crisp.chat/users/helpdesk/website/-/4/1/5/7/415740f4b2c87400/substitutions-c7b98a6fe07f9bcf_gfjrub.png)




## Best practices

To avoid common problems:

* Copy exact content when matching HTML  
* Avoid overly generic words like “the” or “shop”  
* Test your rule on multiple pages  
* Check for domain references inside your replacement  
* Keep rules organized and clearly named  

| Rule of thumb: The more specific your match, the safer your substitution.



## When not to use substitution rules

Substitution rules are not ideal for:

* Large content changes  
* Full page rewrites  
* Complex dynamic content loaded via JavaScript  
* Bulk translation management  

In those cases, consider:

* Translation settings  
* Glossary rules  
* JSON translations  
* The Clone Editor  



## Troubleshooting

If your substitution does not work:

* Check for small spacing differences  
* Verify casing  
* Confirm the content exists exactly as entered  
* Make sure it is not dynamically injected content  

If the content is loaded dynamically, a JavaScript-based approach may be required instead of a static substitution rule.



## Tags
content override, pattern matching, localization control, frontend adjustments, rule engine, automated content swap