Header Must Not Be Longer Than 100 Characters | Normalize CSV Headers

Header Must Not Be Longer Than 100 Characters

Header must not be longer than 100 characters is a common import error when CSV column names come from verbose report labels, concatenated metadata, or auto-generated survey questions. The fastest fix is to shorten and standardize headers before the file is loaded into a database, BI model, or API that enforces header length constraints. This Header Normalizer cleans and standardizes header names and lets you choose an output style such as snake_case, Title Case, uppercase, or lowercase. It also removes spaces and special characters, which helps prevent parsing and mapping bugs caused by punctuation or invisible whitespace. If the CSV contains duplicate header names, the tool ensures uniqueness by appending a suffix, avoiding collisions that otherwise overwrite fields during import. A reliable workflow is to normalize first, then validate the file with the destination system’s rules—header length, allowed characters, and uniqueness—before running a large load. Because the tool expects a header row, it’s best used after confirming the first line is truly column names rather than data. WizardOfAZ positions this as a browser-based way to normalize tabular datasets without extra installs, which is useful for quick remediation during handoffs. Once headers are normalized, keep the cleaned file as the “contract version” so future exports follow the same naming pattern and don’t reintroduce long headers.