When you see "Prompt contains forbidden characters" or the error code FORBIDDEN_CHARACTERS_IN_PROMPT, it means your prompt contains characters or patterns that our system doesn't allow for security reasons.
Only two characters are blocked:
< (less than)
> (greater than)
These are blocked to prevent potential security vulnerabilities.
Besides < and >, a few patterns are also blocked:
4 or more consecutive special characters — e.g. ...., ::::, ---- (3 in a row is fine)
Escape sequences — backslashes, tabs, or line breaks (these can sneak in when you copy-paste text)
Protocol handlers — javascript:, vbscript:, or data: (security precaution)
Almost everything! Your prompts can include:
All letters (A-Z, a-z) and international characters (ä, ö, ü, é, ñ, à, ç, etc.)
Numbers (0-9)
Spaces and common punctuation: . , ( ) : - ' " ! ? @ # $ % & * + = ~ _ [ ] { } | /
Emojis and special Unicode characters
Prompt length
Minimum: 3 characters
Maximum: 5,000 characters
Remove < and > — write "less than" or "greater than" instead
Reduce repeated punctuation — shorten .... to ... or fewer
Type fresh instead of copy-pasting — copied text sometimes contains hidden escape characters or line breaks
If you've followed this guide and still get the error, try retyping your prompt from scratch. If the problem persists, contact our support with the exact prompt text and we'll help you identify the issue.
