Do I need to upload my Excel file?
No. Select the cells in Excel, copy with Ctrl+C, and paste directly into the Input panel. Excel automatically pastes as tab-delimited text — the converter detects the tab delimiter and produces an HTML table. Your spreadsheet file never leaves your computer.
Why use thead and tbody instead of plain rows?
Screen readers, browser print modes, and CSS frameworks all rely on <thead> and <tbody> to distinguish header rows from data rows. Without them, an assistive technology user cannot tell which row is a label and which row is data, and CSS selectors like thead th cannot target the header. The converter always emits both.
How does the converter detect the delimiter?
It checks the first line. If a tab character is present (the format Excel uses when copying cells), the converter splits on tabs. Otherwise it splits on commas with quote-awareness — so "Smith, John",42 becomes two cells, not three.
What does the Full HTML Page checkbox do?
Off (default), the output is just the <table> element — drop it inside any existing page. On, the converter wraps the table in a complete <!DOCTYPE html> document with <head> and <body>, ready to save as a standalone .html file or attach to an email.
Will merged cells from Excel work correctly?
Excel pastes merged cells as the value in the first cell with empty cells for the merged neighbours, so the HTML output reflects that — empty <td>s appear where the merged region used to be. To produce a real rowspan/colspan table, you need to manually edit those cells; the converter cannot infer merge intent from text alone.
Can I add CSS classes for Bootstrap or Tailwind styling?
Yes. The output includes inline border styling so it looks reasonable as-is, but you can find-and-replace <table to <table class="table table-striped" for Bootstrap, or wrap with a Tailwind class on the parent. The HTML structure is standards-compliant and works with any CSS framework.
Is the HTML output safe for email clients?
Yes — and email clients still rely on <table> markup for layout, so this is a common workflow. The converter uses inline styles (style="..."), which is the only style mechanism Outlook supports reliably. Test the output in Litmus or Email on Acid before mass-sending if your audience uses older clients.
Is my data uploaded to your servers?
No. The CSV/TSV parser runs in JavaScript inside your browser. Customer lists, sales figures, and confidential reports never leave your device. Open DevTools Network and click Run — you will see no network requests are made.