Fix invalid Boolean values in a Klaviyo CSV
Boolean properties are strict: Klaviyo documents Boolean import values as true or false; its current data-type guide recommends True and False when uploading Boolean values by CSV. Exports from other systems often contain Yes/No, 1/0 or Y/N instead.
Why the error happens
A column may look Boolean to a person while containing values that do not match the target data type. If the column is mapped as Boolean, values outside true and false can produce invalid-format errors.
Safe conversion
ReadyRows recognizes common unambiguous equivalents such as Yes/No and 1/0 and normalizes them to True/False for the repaired CSV. Unknown values remain warnings rather than being guessed.
When to map as Text instead
If a column contains mixed states that are not genuinely two-valued, mapping it as Text may be safer than forcing it into Boolean.
Official reference
Klaviyo documents Boolean values and mismatched data types in its invalid format troubleshooting guide.
Check the file before you re-import it
ReadyRows scans CSV and XLSX files locally, separates blocking rows and generates an import-ready CSV plus a mapping guide.
Open the free fixerReadyRows is an independent tool and is not affiliated with Klaviyo. Product rules can change; for account-specific decisions, confirm the latest guidance in Klaviyo's Help Center.