Sort a reference list alphabetically

Guide written by the AI for Research editorial team · Last reviewed 14 November 2026

To sort references alphabetically, order every entry by the surname of its first author, letter by letter, so that "Brown" comes before "Browning" because nothing precedes something. Entries with the same first author go one-author works first, then by co-author, then by year, with "n.d." before dated works. Entries with no author go under the first significant word of the title, skipping A, An and The. The sorter above applies these APA 7 rules, or MLA 9 rules if you choose them, and finds duplicates you can remove.

How do you alphabetize an APA reference list?

Sort by the first author's surname, letter by letter, then use the initials, the co-authors and the year to break ties. The APA Publication Manual sets out the order in its section on the reference list [1][4].

The rules, in the order the sorter applies them:

1. First author's surname, letter by letter. Spaces and punctuation inside a name do not count, so "De Vries" files as "devries".
2. Nothing precedes something. A shorter name that matches the start of a longer one comes first. APA's own illustration is "Brown, J. R." before "Browning, A. R." [1].
3. Same surname, different initials. Use the initials, with the same rule: "Baddeley, A." before "Baddeley, A. D."
4. Same first author. One-author works come before works with co-authors. Works with co-authors are ordered by the second author's surname, then the third, and so on.
5. Same author or authors. Order by year, oldest first. "n.d." (no date) comes before dated works and "in press" comes last.
6. Same authors and same year. Order by title and label the years 2020a, 2020b. The sorter keeps the letters you already have and orders by them.
7. No author. Move the title into the author position and file it under the first significant word, ignoring A, An and The.

Worked example (APA 7)

Pasted in this order:

• Walker, M. P., & Stickgold, R. (2004). Sleep-dependent learning and memory consolidation. Neuron, 44(1), 121–133. https://doi.org/10.1016/j.neuron.2004.08.031
• Baddeley, A. D., & Hitch, G. (1974). Working memory. In G. H. Bower (Ed.), Psychology of learning and motivation (Vol. 8, pp. 47–89). Academic Press. https://doi.org/10.1016/S0079-7421(08)60452-1
• Walker, M. P. (2017). Why we sleep. Scribner.
• Baddeley, A. (2012). Working memory: Theories, models, and controversies. Annual Review of Psychology, 63, 1–29. https://doi.org/10.1146/annurev-psych-120710-100422
• Baddeley, A. (2000). The episodic buffer: A new component of working memory? Trends in Cognitive Sciences, 4(11), 417–423. https://doi.org/10.1016/S1364-6613(00)01538-2

Sorted:

1. Baddeley, A. (2000): one author, earliest year.
2. Baddeley, A. (2012)
3. Baddeley, A. D., & Hitch, G. (1974): "A." is shorter than "A. D.", and the entry has a co-author, so it follows both one-author entries even though its year is the earliest.
4. Walker, M. P. (2017): one author.
5. Walker, M. P., & Stickgold, R. (2004): co-authored, so after the one-author Walker entry.

Entries 3 and 5 are the ones people get wrong most. The year only decides the order when the author lists are identical.

How is an MLA Works Cited list ordered?

MLA 9 also sorts by the first element of each entry, which is usually the author's surname, and ignores A, An and The at the start of a title [2]. The differences from APA are in the tie-breaks.

• Several works by the same author are ordered by title, not by year. In the printed list, the second and later entries replace the name with three hyphens [2][3].
• A work by one author comes before works that author wrote with others.
• Entries that start with a title are filed under the first word other than A, An or The.

Worked example (MLA 9)

The sorter does not add the three hyphens. Add them after sorting if your instructor asks for them.

APA and MLA order side by side

How does the duplicate check work?

Two entries are flagged as duplicates when they share a DOI, are the same entry with different punctuation, or have the same title and year. Entries with the same title but different years, or very similar titles by the same first author in the same year, are flagged as likely duplicates for you to check.

Duplicates usually come from merging lists, for example a Zotero export and a list typed by a co-author. Paste the Walker and Stickgold (2004) entry above twice, once in sentence case and once in title case without the DOI. The titles and years match, so the tool flags the pair as a duplicate and offers to remove the second copy.

Likely duplicates need a person to decide. A conference paper and the later journal article often share a title but are different works with different years. You may need to cite both, or only the one you read. Two entries with different DOIs are never paired, however alike their titles look.

Common mistakes

• Sorting by year first. APA uses the year only after the author list.
• Treating "The" as the first word. "The ethics of data sharing" files under "ethics".
• Mixing up one person's initials. "Baddeley, A." and "Baddeley, A. D." sort as different names. If they are the same person, use the same initials in every entry, as the source gives them.
• Guessing at prefixes. Follow how the person writes their own name. The sorter treats a capitalized prefix written first ("De Vries") as part of the surname.
• Numbering an author-date list. APA and MLA lists are not numbered. The sorter removes [1] and 1. from the start of each entry.
• Keeping both copies of a duplicate. Reference managers merge items on import, but pasted lists do not.
• Expecting the sorter to fix the format. It changes the order only. To reformat entries, use the citation formatter.

What the sorter cannot do

It reads names and years from the text of each entry. Unusual layouts can confuse it: a list with no years, names in all capitals, or an entry that wraps without a full stop at the end. Check any entry that lands in an odd place. It also cannot tell whether two people with the same surname and initials are the same person.

How to keep a reference list tidy with AI for Research

Build the list in the free citation generator by pasting a DOI or title, then sort it here. To check that each citation in your paper has a list entry, paste the paper into the citation coverage checker. In the editor, import from Zotero or Mendeley and the list is ordered for you in any of 10,000+ styles. Citations, search and the free tools cost nothing. The Free plan also has 45 credits a month for the AI features.

FAQ

How do I sort references alphabetically in APA?

Sort by the first author’s surname, letter by letter, so Brown comes before Browning. For the same first author, put one-author works first, then works with co-authors ordered by the next author’s surname. For identical authors, order by year with n.d. first and in press last. Works with no author are filed under the first significant word of the title.

Does APA order by year or by author?

By author first. The year only decides the order when the author lists are the same, in the same order. So Baddeley, A. (2012) comes before Baddeley, A. D., & Hitch, G. (1974), because a one-author entry comes before any entry where the same name is followed by co-authors, whatever the years.

How do you alphabetize references with no author?

Move the title into the author position and file it under its first significant word. Skip A, An and The, so a title beginning “The ethics of data sharing” files under “ethics”. When a group, such as the World Health Organization, is responsible for the work, use the group as the author, because a group author is an author.

How are works by the same author ordered in MLA?

By title, ignoring A, An and The, not by year. In the printed list the author’s name appears in the first entry only and is replaced by three hyphens in the entries after it. Works the author wrote alone come before works written with co-authors. The sorter orders the entries; add the hyphens yourself.

Is my reference list uploaded anywhere?

No. The sorter runs in your browser. The list you paste is not sent to a server or saved, so it is gone when you close the page. Copy the sorted list before you leave, and paste it over the old list in your paper. Nothing is stored in an account either.

Next steps

• Read the full rules for APA reference lists and MLA Works Cited.
• See how to format a reference list in APA, Vancouver, IEEE and Harvard.
• Check your in-text citations against the list with the citation coverage checker.

Sources

1. American Psychological Association. (2020). Publication manual of the American Psychological Association (7th ed.). https://doi.org/10.1037/0000165-000
2. Modern Language Association of America. (2021). MLA handbook (9th ed.). Modern Language Association of America.
3. MLA Style Center. Modern Language Association. https://style.mla.org/
4. American Psychological Association. References. APA Style. https://apastyle.apa.org/style-grammar-guidelines/references