Clean by Similarity API finds duplicate contacts, leads, and company names in your spreadsheets — even when they're spelled differently across records. Unlike Excel's Remove Duplicates or your CRM's built-in deduplication, Clean uses fuzzy matching to catch real-world variants: "Acme Corp" and "Acme Corporation", "Jen Walsh" and "Jennifer Walsh", "Microsoft" and "Microsoft Inc." are all correctly identified as duplicates. Exact-match tools miss these entirely. Upload a CSV or Excel file, select which columns to match on, and preview your duplicate clusters before downloading. Match on a single column or combine name and company together for more reliable results — combining two weak signals into one strong match decision. Three output formats: a clean file with duplicates removed, your original file flagged with cluster IDs, or a review sheet showing duplicate groups with similarity scores for manual inspection before merging. Free for files up to 1,000 rows, no account required. Larger files from $4.99 per run — pay once, download immediately, no subscription needed. Built for marketing ops, RevOps, and anyone who needs a clean file before a CRM import, not a coding project.