Extract, clean and deduplicate DOIs from reference lists and flag malformed ones.
How to use DOI Extractor
Paste your reference list, bibliography or any text.
Choose whether to remove duplicates and how to format the output.
Copy the DOIs or download them as TXT or CSV, and review any flagged lines.
Worked example
“…Lancet. 2020;395:497-506. https://doi.org/10.1016/S0140-6736(20)30183-5.” gives 10.1016/S0140-6736(20)30183-5, keeping the brackets and dropping the final full stop.
Are DOIs case-sensitive?
No. 10.1136/BMJ.N71 and 10.1136/bmj.n71 are the same DOI, so duplicates are matched without regard to case.
Why is a line flagged?
It mentions a DOI that could not be read, often because it was split across two lines or is missing the 10. prefix.
Put this guide into practice
DOI Extractor — Extract, clean and deduplicate DOIs from reference lists and flag malformed ones.