Workflow · 3 min read
How to Clean Large Tag Lists
A step order for repairing a list of hundreds of tags without losing anything you need.
Why lists decay
Tag lists degrade because they travel. Text copied out of a spreadsheet arrives with quotes and trailing spaces; text copied from a caption arrives as one long hashtag block; text from an export arrives semicolon-separated. Each trip adds a small inconsistency, and after enough trips the list contains three versions of the same tag.
The right order of operations
Split on separators first, so every entry is genuinely separate. Trim whitespace next. Then normalise case and hash symbols, because deduplication only works once entries look alike. Deduplicate after that, not before. Sort last, if you need it.
Doing this in the wrong order is the usual reason a cleaned list still contains duplicates: entries that differ only by a trailing space or a capital letter survive a deduplication pass that runs too early.
Check before you commit
Count the result and compare it with the original count. A large drop is normal for a decayed list, but a drop of more than half is worth inspecting — it usually means an option removed something you wanted, such as stripping hash symbols from a set you intended to keep as hashtags.