I get the error 'Prompt contains forbidden characters'. Why?

What Does This Error Mean?

When you see the error message "Your prompt contains unsupported characters" or encounter the error code FORBIDDEN_CHARACTERS_IN_PROMPT, it means your prompt contains one or more characters that our system doesn't allow for security and technical reasons.

This validation happens to protect both you and our platform from potential security vulnerabilities and to ensure your prompts work correctly with our AI models.

What Characters ARE Allowed?

Your prompts can include:

Letters & Numbers

• All letters: A-Z, a-z

• International characters: ä, ö, ü, é, ñ, à, ç, and other accented letters

• Numbers: 0-9

Spaces & Basic Punctuation

• Spaces (regular spaces between words)

• Period: .

• Comma: ,

• Parentheses: ( and )

• Hyphen/Dash: -

• Single quote: '

• Double quote: "

• Colon: :

Special Rules

• Question marks (?) and exclamation points (!) are automatically converted to periods (.) - so you can use them, but they'll be changed before processing

Prompt Length

• Minimum: 3 characters (though we recommend at least 5 for better results)

• Maximum: 1,000 characters

What Characters Are NOT Allowed?

The following characters are blocked for security reasons:

Brackets & Braces

• Square brackets: [ ]

• Curly braces: { }

• Angle brackets: < >

Special Symbols

• Pipe: |

• Backslash: \

• Backtick: `

• Tilde: ~

• Hash/Pound: #

• Percent: %

• Caret: ^

• Ampersand: &

• Asterisk: *

• Plus: +

• Equals: =

• At sign: @

• Dollar sign: $

• Underscore: _

Special Sequences

• Tab characters (invisible spacing)

• Line breaks (pressing Enter mid-prompt)

• Multiple consecutive punctuation (3 or more in a row): ..., ---, :::, etc.

• URL protocols: javascript:, http://, data:, etc.

Why These Restrictions?

These character restrictions exist to:

1. Prevent security vulnerabilities - Some characters can be used for code injection attacks

2. Ensure reliable processing - Special characters can confuse AI models

3. Maintain system stability - Certain patterns could cause processing errors

4. Protect your account - Prevents malicious prompt manipulation

Common Mistakes & How to Fix Them

Example 1: Email Addresses or Usernames

Won't Work: Create an image for @john_smith's profile

Fix: Create an image for John Smith's profile

Example 2: Percentages or Math

Won't Work: Show 50% of the background in blue & 50% in red

Fix: Show half of the background in blue and half in red

Example 3: Hashtags or Tags

Won't Work: A sunset scene #beautiful #nature

Fix: A beautiful sunset scene in nature

Example 4: Code or Technical Terms

Won't Work: A robot with <arm> and [sensor_array]

Fix: A robot with mechanical arms and sensor arrays

Example 5: Web URLs or Links

Won't Work: A style like https://example.com/style

Fix: A modern minimalist style

Example 6: Excessive Punctuation

Won't Work: A cat with really... really... really big eyes!!!

Fix: A cat with extremely large eyes

Note: The multiple exclamation points are converted to periods, but three consecutive periods (...) are not allowed

Best Practices for Writing Valid Prompts

1. Use Natural Language

Write your prompts as you would describe the image to another person:

• Good: "A cozy coffee shop with warm lighting"

• Bad: "Coffee_shop [warm] & cozy"

2. Spell Out Special Terms

Instead of using symbols, write out what you mean:

• Good: "fifty percent blue, fifty percent red"

• Bad: "50% blue & 50% red"

3. Avoid Copy-Pasting from Other Sources

Content copied from websites, code editors, or social media often contains hidden special characters. If you must copy text:

1. Paste it into a plain text editor first

2. Remove any special formatting

3. Then use it in your prompt

4. Keep It Simple

The more straightforward your prompt, the less likely you'll hit validation errors:

• Good: "A red sports car on a mountain road"

• Bad: "A red sports car {fast} on a mountain road [scenic]"

5. Check for Invisible Characters

Sometimes you might accidentally include:

• Tab characters (from pressing Tab)

• Line breaks (from pressing Enter)

• Special spaces (from copying formatted text)

Tip: If you get an error but can't see any special characters, try typing the prompt fresh instead of copying/pasting it.

Quick Troubleshooting

If you're getting this error:

1. Remove any symbols that aren't in the "allowed" list above

2. Replace special characters with words (e.g., & becomes "and", % becomes "percent")

3. Check for consecutive punctuation (reduce ... to . or ,)

4. Retype instead of copy-paste if the error persists

5. Keep it conversational - write as you would speak

Still Having Issues?

If you've followed this guide and are still experiencing problems:

1. Check your prompt length - must be 3-1000 characters

2. Try a simpler version of your prompt first

3. Contact support with the exact prompt text that's failing (we can help identify the issue)

Remember: These restrictions help keep our platform secure and ensure the best results for your image generation. With a little adjustment, you can express any creative idea using the allowed characters.