How do I convert ISBN-10 to ISBN-13?

The tool validates the ISBN-10 checksum, removes its check character, prepends 978 and calculates the new ISBN-13 check digit. For example, 0306406152 becomes 9780306406157.

Why can a 979 ISBN not convert to ISBN-10?

ISBN-10 corresponds to the 978 ISBN-13 prefix. Valid 979 numbers have no ISBN-10 equivalent, so the tool explains that result instead of inventing a value.

What does X mean in an ISBN-10?

X represents a check value of ten and is allowed only in the last position of an ISBN-10. Lowercase x is accepted and normalized to uppercase. ISBN-13 check digits are always numeric.

Does a valid checksum prove the book exists?

No. This tool validates format and checksum only. It does not query a book catalogue, check publisher assignment or identify a title.

Can I paste ISBNs with hyphens and spaces?

Yes. Spaces and hyphens are removed before validation. Put each ISBN on its own line. Output is unhyphenated because publisher and registration-group boundaries are not inferred.

What does the CSV include?

Every nonblank input line, normalized ISBN, validity, converted value and explanation. Invalid rows and nonconvertible 979 numbers remain in the report. The copied conversion list includes only successfully converted values.

Are batch inputs stored or uploaded?

No. Processing happens locally and the tool does not save inputs between visits. A batch can contain up to 10,000 lines and 500,000 characters. The results table shows 100 rows per page, while export includes the full batch.

ISBN Converter

Paste one ISBN per line to check its format and checksum. Valid ISBN-10 values convert to ISBN-13, and valid 978 ISBN-13 values convert back to ISBN-10. Every row keeps its original line number, including invalid entries and valid 979 numbers that have no ISBN-10 equivalent. Copy the conversions or download the full CSV report.

ISBNs, one per line

0 ISBNs · 0 valid checksums · 0 invalid · 0 convertible

Checksum/format only; no book metadata lookup or proof a number was assigned. Inputs stay in this tab and are not saved. Output is unhyphenated; publisher grouping is not inferred.

Common questions

How do I convert ISBN-10 to ISBN-13?: The tool validates the ISBN-10 checksum, removes its check character, prepends 978 and calculates the new ISBN-13 check digit. For example, 0306406152 becomes 9780306406157.
Why can a 979 ISBN not convert to ISBN-10?: ISBN-10 corresponds to the 978 ISBN-13 prefix. Valid 979 numbers have no ISBN-10 equivalent, so the tool explains that result instead of inventing a value.
What does X mean in an ISBN-10?: X represents a check value of ten and is allowed only in the last position of an ISBN-10. Lowercase x is accepted and normalized to uppercase. ISBN-13 check digits are always numeric.
Does a valid checksum prove the book exists?: No. This tool validates format and checksum only. It does not query a book catalogue, check publisher assignment or identify a title.
Can I paste ISBNs with hyphens and spaces?: Yes. Spaces and hyphens are removed before validation. Put each ISBN on its own line. Output is unhyphenated because publisher and registration-group boundaries are not inferred.
What does the CSV include?: Every nonblank input line, normalized ISBN, validity, converted value and explanation. Invalid rows and nonconvertible 979 numbers remain in the report. The copied conversion list includes only successfully converted values.
Are batch inputs stored or uploaded?: No. Processing happens locally and the tool does not save inputs between visits. A batch can contain up to 10,000 lines and 500,000 characters. The results table shows 100 rows per page, while export includes the full batch.

Checksum/format only; no book metadata lookup or proof a number was assigned.