Formula to validate single-line text field input

[John_Zimmerman]

Hi, folks. We’re about to do a big import, and I was wondering what is the maximum character length of a single line text field. Thanks.

[Justin_Barrett]

I don’t think the maximum length is documented anywhere, at least not that I’m aware of. I just ran a test, though, filling a formula field by repeating a single character based on a count set in another field, then converted that to a single line text field. I also added another formula field to confirm that the character sequence wasn’t being truncated. I got up to 10 million characters before things started to bog down, so I didn’t test any further. :slightly_smiling_face:

[John_Zimmerman]

Hey, Justin. Clever test! Thanks for your help. :grinning:

[Tim_Mackey]

This appears to be an exception to the rule, perhaps to prevent data loss when converting field types. The default maximum for text fields is 100,000 characters, as reported elsewhere: What is the long text character limit?

I ran into this issue when generating JSON data from my Airtable base, if you attempt to go over the limit while using a script, it will return an error similar to <root> is longer than the maxLength: 100000