Supported file types:
- Microsoft Excel (.xlsx)
- Comma separated (csv)
- Tab separated (.tsv, .tab)
- Text (.txt,.md)
Your file will be processed and a converted version will be downloaded automatically.
Frequently Asked Questions
What file types does the file converter support?
ISBNConverter.com accepts Microsoft Excel (.xlsx), comma-separated (.csv), tab-separated (.tsv, .tab), plain text (.txt), and Markdown (.md) files. The converter detects ISBNs regardless of surrounding text or column headers. Structured formats (Excel, CSV, TSV) support the column placement options; unstructured formats (.txt, .md) use in-place replacement only.
What do the column placement options mean?
For Excel, CSV, and TSV files, you can choose where the converted ISBNs appear in the output: immediately after the source column (After), before it (Before), at the very end of each row (End of row), at the start of each row (Start of row), or replacing the original value entirely (In place). For plain text and Markdown files, only In Place is available: the converted code replaces the original in its existing position.
Does ISBNConverter.com modify my original file?
No. ISBNConverter.com processes a copy of your uploaded file and delivers the result as a download. Your original file is never stored or modified. Uploaded files are deleted from our servers immediately after processing is complete. No data is retained.
Are there file size limits?
There is no enforced maximum file size. Files with tens of thousands of rows process reliably. Very large uploads may take a few seconds longer, but conversion runs to completion. Each ISBN that is successfully converted consumes one credit.
What if some ISBNs in my file cannot be converted?
ISBNs that fall outside the convertible range (such as "979"-prefixed EANs when converting to ISBN-10, or codes that fail checksum validation) are left unchanged in the output file. All other ISBNs are converted normally. No rows are dropped or omitted from the downloaded file; unconvertible codes simply remain as they were. To convert a mixed list without a file structure, the bulk ISBN converter accepts plain text input directly.