What is CSV and Excel export?
CSV and Excel export lets users download data from your app as a spreadsheet file — ready to open in Excel, Google Sheets, or import into another system. A "Download to CSV" button is one of the most frequently requested features in business software, because users always want to take data somewhere: their accountant's inbox, a pivot table, a mail merge, a board report.
CSV (comma-separated values) is the simplest format — plain text, universally compatible. XLSX (the Excel format) supports formatting, multiple sheets, formulas, and column widths, making it more appropriate when the exported file needs to look polished or be used directly rather than imported elsewhere.
For any app that stores tabular data — bookings, contacts, orders, timesheets, transactions — export is a near-universal requirement.
When does your app need it?
- Users need to share data with people who don't have access to your app (accountants, managers, clients)
- Your app captures records that users also maintain in Excel or need to reconcile with other systems
- Compliance or reporting requires periodic data extracts in a standard format
- Users want to run their own analysis — pivot tables, custom formulas — that your app's reporting doesn't cover
- You need to support data portability so users can leave your platform without feeling locked in
- Your app needs to send scheduled data exports automatically via email on a daily or weekly basis
How much does it cost?
Adding CSV and Excel export typically adds 3–5 hours of development — roughly from $1,000 AUD at Australian boutique agency rates.
A simple CSV of the current table view (same columns, same filters applied) sits at the very low end. XLSX export with formatting, multiple sheets, column selection UI, or very large datasets (where you need streaming to avoid memory issues) adds time. Scheduled automated exports, delivered by email on a recurring basis, add another few hours.
How it's typically built
CSV generation can be done client-side (in the browser using Papa Parse or simple string construction) for small to medium datasets. For larger exports, server-side generation is more reliable — the API queries the database, transforms the results, and streams the file to the browser.
XLSX files are generated using libraries like ExcelJS or the xlsx package, which support rich formatting: bold headers, column widths, number formatting, multiple sheets. ExcelJS is particularly well-suited for formatted reports; xlsx is lighter and faster for raw data exports.
For very large datasets (tens of thousands of rows), streaming export is important — rather than loading everything into memory and then writing, the file is written row-by-row as the database cursor is consumed. This keeps memory usage flat regardless of export size.
Scheduled exports are handled by a cron job (e.g., AWS EventBridge, Vercel Cron) that generates the file and sends it as an email attachment via a service like Resend or SendGrid.
Questions to ask your developer
- Client-side or server-side generation? Client-side is simpler but can freeze the browser tab on large datasets; server-side is more robust.
- Should users be able to choose which columns to export? A column selector UI adds time but is very useful when the table has many fields.
- Do we need to export filtered data, or always everything? Exporting the current filtered view is usually what users want — make sure the export respects any active filters.
- Is there a maximum row count we should enforce? Very large exports (100,000+ rows) can time out or consume excessive server resources — discuss limits and async handling.
- Do we need scheduled/automated exports? If yes, define the schedule, recipients, and format upfront as this is a distinct piece of work.
See also: PDF report generation · Bulk data import · App cost calculator