How to extract DOI from text
Paste references, citations, or document text into DOI Extractor. As you type, it lists DOI-shaped identifiers such as 10.1000/xyz123, shows the source line and nearby text, and creates a doi.org URL for each row. Unique only starts checked, so repeated identifiers are reduced to the first occurrence.
Which DOI formats can DOI Extractor find?
A candidate starts with 10., has 4 to 9 digits, a slash, and a suffix without spaces. DOI Extractor accepts bare strings and these prefixes: https://doi.org/..., http://dx.doi.org/..., dx.doi.org/..., www.doi.org/..., and doi:. It removes the URL or doi: prefix before display, then trims citation punctuation at the end.
The results table shows DOI, doi.org URL, Line, and Context. Rows keep their source order. Unique only removes later matches whose lowercase DOI key has already appeared.
Smith, J. (2020). A study of things. https://doi.org/10.1000/xyz123
Doe, A. (2019). Another study. doi:10.5555/1234567810.1000/xyz123
10.5555/12345678How do Unique only and Normalize change DOI results?
Unique only is checked when the page loads. It compares lowercase keys and keeps the first match, so case differences do not create additional rows. Uncheck Unique only to retain repeated matches in source order.
Normalize (lowercase, strip URL prefix) lowercases the displayed DOI and the displayed URL. DOI Extractor removes URL and doi: prefixes in both settings. Normalize changes case; it does not change which prefix was removed.
How to review and export DOI matches
- Paste references, citations, or document text into the input area.
- Select Upload to choose a
.txt,.csv,.json,.log,.md,.bib, or.ristext file. - Review the count and the DOI, doi.org URL, Line, and Context columns as the list updates while you type or change an option.
- Select Copy to copy the output, or Download to save it as
dois.txt.
When entered text contains no DOI-shaped candidates, the status says so, the output stays empty, and the count reads 0 DOIs found. Copy and Download remain disabled until at least one DOI is listed. With an empty text box, the results section stays hidden.
What the extracted DOI list contains
The text box contains one displayed DOI per line. The table adds a URL, the source line number, and a shortened context snippet for each retained match.
Upload accepts the listed text file extensions, then places the file text into the input area. The page reads and processes that text in the browser. It does not send the entered content to a server.
Use the table when a DOI-shaped candidate needs checking against its surrounding reference. The Context column is built from text near the match, and Line identifies where the match begins.
When to use another text extractor
Use Text Parsing & Data Extraction for a different text pattern. Choose Custom Regex Extractor when you need your own JavaScript regular expression or capture groups. Choose Extract Emails from Text for email addresses, domain filtering, or lowercase output.
Frequently asked questions
How do I extract DOI from a reference list?
Paste the reference list into the input area. DOI Extractor updates the DOI list, count, and source details as the text changes.
Can DOI Extractor find doi.org URLs?
Yes. It finds DOI-shaped values in doi.org, dx.doi.org, and www.doi.org URL forms, with or without an HTTP or HTTPS protocol.
Does DOI Extractor verify a DOI?
DOI Extractor detects DOI-shaped strings and creates a doi.org URL for review. It does not contact doi.org, check registration, resolve links, or retrieve publication metadata.
How does Unique only handle repeated DOIs?
Unique only compares lowercase keys and displays the first occurrence of each repeated DOI. Uncheck it to keep repeated matches in source order.