document
CSV to XLSX converter
Free online CSV → XLSX conversion. 3 free per day, no signup. Files auto-delete after 24 hours.
Common questions
- How do I convert CSV to XLSX?
- Upload your CSV file using the form above, select XLSX as the target format, and click "Convert". The first 3 conversions per day are free. Your file is processed on our servers and deleted after 24 hours.
- Is converting CSV to XLSX free?
- Yes, the first 3 conversions per day are free with no account required. After that, the Pro plan (€9/month) gives you 100 conversions per day, Bulk (€19/month) is unlimited, and the API plan (€49/month) supports programmatic conversion at scale.
- Will the output file be the same quality as the source CSV?
- XLSX can losslessly represent the contents of a CSV file in most cases. We preserve the original quality unless explicitly downsampled.
- What's the maximum CSV file size I can convert?
- Free: 10 MB. Pro: 100 MB. Bulk: 1 GB. API: 5 GB. Files larger than the limit return a 413 error with the exact size and the smallest tier that would accept it.
- Is the CSV to XLSX conversion safe?
- Yes. Files are uploaded over HTTPS, processed in isolated workers, and deleted from our servers within 24 hours. We never inspect file contents or share data with third parties. The conversion happens on our infrastructure (not in your browser), so the source is briefly stored - see our Privacy page for the exact retention policy.
- Can I convert CSV to XLSX in bulk via API?
- Yes. The API plan (€49/month) gives you a Bearer token to authenticate at https://bulkconvert.io/api/v1/convert. Each call accepts a source URL and target format, returns a download URL. Up to 10,000 conversions per month. See /docs/api for the full reference.