If you want to control what shoppers can type into a text input or textarea, you can limit the number of characters they can enter or restrict the type of characters allowed (letters, numbers, spaces, etc.). This helps ensure the personalization fits your design and avoids unexpected formatting.
You can:
Limit the number of lines and characters per line (for textareas).
Restrict input type to only allow specific kinds of characters.
Limit the Maximum Number of Characters
Go to your Option Sets panel and select the set you want to edit.
Click on the Text Input Option you want to edit to expand its settings.
In the Max Length field, enter the number of characters you want to allow. Keep in mind Max Length counts spaces as characters.
Save your changes.
When setting a Max Length, a counter will appear next to the option's label, showing how many characters have been typed and what the maximum allowed is.
Limit the number of lines and characters per line (for Text Area only)
Go to your Option Sets panel and select the set you want to edit.
Click on the Text Input Option you want to edit to expand its settings.
Make sure the input is marked as a Textarea
Set Max Number of Lines to limit maximum number of lines allowed. And Max. Characters Per Line to cap the length of each line. You can use one or both settings.
Save your changes
Tip
You can also use Max Length together with Max Lines and Characters Per Line. This creates multiple limits at once (useful for strict layouts), but it can feel restrictive—use thoughtfully.
Restrict Input Type (Letters, Numbers, Custom Rules)
Go to your Option Sets panel and select the set you want to edit.
Click on the Text Input Option you want to edit to expand its settings.
-
Find Restrict Input and choose a rule:
→ No restriction (default)
→ Only numbers (with spaces)
→ Only numbers (NO spaces)
→ Only letters (with spaces)
→ Only letters (NO spaces)
→ Custom (restrics specific words with Regex expression) Save your changes
Tip
If you're restricting the input, explain it in the Help Text so shoppers know exactly what to type. For example: “Only letters allowed” or “Numbers only.” Without guidance, it can be frustrating for shoppers if their input doesn’t appear and they don’t understand why.
How to restrict specific words with Custom Regex Expressions
Custom regex (regular expressions) let you create your own advanced rules for what shoppers can and cannot type. They’re useful for things like:
Blocking specific words or phrases.
Enforcing a format
Combining multiple rules into one.
- Under Restrict Input, select Custom
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Enter the words you'd like to restrict using ( ) and separating each word with a | . For example
(fudge|shoot|dang)This would block shoppers from typing the words fudge, shoot and dang.
Save your changes
Tip
Most merchants use presets for common restrictions, but Custom Regex is perfect for advanced scenarios — like requiring certain words, disallowing specific characters or symbols, or enforcing a specific format. If you’re not familiar with regex, you can use an online regex generator or ask ChatGPT to write one for you. Always test to make sure valid inputs are accepted and only unwanted ones are blocked.