Upload two spreadsheets (CSV or Excel), pick the shared key column, download the merged file. Nothing leaves your browser.
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Drag and drop your primary file (File A) and lookup file (File B). Supports CSV, XLSX, and XLS formats.
Pick the shared unique identifier (e.g. Email or Domain) and choose which columns from File B to append.
Preview matched rows, check match percentages, and download your clean merged file in 1 click.
Every sales operations analyst has struggled with Microsoft Excel freezing when running =VLOOKUP or =XLOOKUP across 50,000+ rows.
Traditional spreadsheet lookups are computationally expensive, prone to reference breakage when columns shift, and return frustrating #N/A or #REF! errors whenever whitespace or casing varies.
Instead of scanning row-by-row like Excel formulas, our merger constructs an O(1) hash table in your browser's memory. It joins tens of thousands of records in fractions of a second with zero lag.
The algorithm automatically trims hidden trailing whitespace and normalizes case, ensuring that matches are not lost due to slight spreadsheet formatting discrepancies.
If File B contains multiple rows with the same key, the merger retains the first instance. To ensure clean 1-to-1 matching, you can first clean File B using our DeDupe List Tool.
Yes! You can mix and match formats. For example, File A can be a CSV export from Apollo or LinkedIn, and File B can be an XLSX export from Salesforce.
If both files share identical column names (e.g. "Status"), the merger automatically appends a "_B" suffix to File B's column to prevent data collisions.
Read our end-to-end framework on list hygiene, deduplication, and CRM upload safety.
Enrichverx connects multi-provider waterfall enrichment directly to your CRM. Inbound leads are matched, verified, and scored in real-time.