The latest articles on DEV Community by Rocquemont (@d0ctor64). https://dev.to/d0ctor64 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4194606%2Fd67552fb-c8c0-479b-bcbc-3d3792f85e73.jpeg https://dev.to/d0ctor64 en Rocquemont Mon, 19 Oct 2026 17:30:35 +0000 https://dev.to/d0ctor64/how-to-clean-messy-csv-excel-files-in-1-click-without-uploading-your-data-to-a-server-41dn https://dev.to/d0ctor64/how-to-clean-messy-csv-excel-files-in-1-click-without-uploading-your-data-to-a-server-41dn <p>If you work with <strong>CRM exports</strong>, <strong>accounting spreadsheets</strong>, or <strong>HR lists</strong>, you know the pain of messy <code>.csv</code> and <code>.xlsx</code> files:</p> <ul> <li>Dates mixed between <code>DD/MM/YYYY</code> and <code>YYYY-MM-DD</code> </li> <li>Invisible trailing spaces that break <code>VLOOKUP</code> / <code>XLOOKUP</code> </li> <li>Duplicate rows and <code>#REF!</code> / <code>#N/A</code> errors</li> <li>Inconsistent casing and typos in city or company names</li> </ul> <p>The biggest problem? <strong>Privacy.</strong> If your spreadsheet contains customer emails, phone numbers, or salaries, GDPR and company security policies forbid you from uploading that file to ChatGPT or random cloud converters.</p> <p><em>The Local-First Solution: Tidify</em></p> <p>To solve this, I built <strong><a href="https://tidify-app.netlify.app/" rel="noopener noreferrer">[Tidify]</a></strong>, a free browser-based data cleaning workspace.</p> <p>Instead of uploading your spreadsheet to a remote server, Tidify parses and cleans your <code>.csv</code> or <code>.xlsx</code> file <strong>100% locally inside your browser's RAM</strong> (via WebAssembly/JavaScript).</p> <p><em>What it fixes in 1 click:</em></p> <ol> <li><strong>Strict Deduplication &amp; Empty Row Purge</strong></li> <li> <strong>Date &amp; Currency Standardization</strong> (ISO <code>YYYY-MM-DD</code>, <code>DD/MM/YYYY</code>, numeric salaries)</li> <li> <strong>Contact Normalization</strong> (emails lowercased, phone numbers formatted, names capitalized)</li> <li> <strong>Cell-by-Cell Diff &amp; Audit Report</strong> so you can verify every single change before exporting back to <code>.xlsx</code> or <code>.csv</code>.</li> </ol> <p>You can try it right now in your browser (available in English, French, German, Spanish, and Portuguese):<br> 👉 <strong><a href="https://tidify-app.netlify.app/" rel="noopener noreferrer">Launch Tidify (Free)</a></strong></p> privacy productivity tools