Alphabetize references by the first author's surname, letter by letter. Use initials or first names if the same surname appears twice. If there's no author, put an entry by its title and skip a first A, An or The. APA, MLA and Chicago agree on these basics. They differ mostly on what comes next: how to sort several works by one author. APA puts them in order of year; MLA and Chicago bibliographies put them in order of title.
APA 7 explains its rules for sorting in chapter 9 of the Publication Manual, in the section on the order of works in the reference list. The MLA Handbook (9th edition) and The Chicago Manual of Style (17th edition) explain them in their chapters on works cited lists and bibliographies.
The basic rules of reference list alphabetical order
Reference list alphabetical order depends on the first element of each entry. Four rules settle most lists:
- File by the first element: the first author's surname, or the title when there is no author.
- Nothing precedes something: a surname that ends first comes before a longer one with the same opening letters, so Hall comes before Hallam.
- When two surnames are identical, compare the initials (APA) or the first names (MLA and Chicago).
- Skip A, An and The at the start of a title.
In this sorted example, each entry is cut to the parts that decide the order.
Ekwueme, C. (2022). The ethics of field notes. (2020). Hall, D. K. (2023). Hall, T. (2021). Hallam, B. (2019).
The ethics of field notes goes under E, because The is skipped. It follows Ekwueme, since "ek" comes before "et". Hall, D. K. comes before Hall, T. because D comes before T, and both come before Hallam.
An annotated bibliography follows the same order, with each annotation directly under its entry. Our guide on how to write an annotated bibliography shows two sorted entries with their annotations.
APA reference list alphabetical order
APA reference list alphabetical order adds a fixed sequence for entries that share a first author:
- Works by that author alone come first, oldest year first. A work with no date (n.d.) goes before the dated ones, and a work in press goes last.
- Works where the same author has coauthors come next, sorted by the second author's surname, then the third.
- Works with the same authors in the same order are sorted by year.
- Works with the same authors and the same year are sorted by title, skipping A, An and The. You then add a, b and c after the year, and the in-text citations use the same letters.
When two first authors share a surname, APA sorts them by initials. The list has ten works by two authors named Okafor:
Okafor, N. (n.d.). Okafor, N. (2018). Okafor, N. (2021a). Access to care in coastal towns. Okafor, N. (2021b). The rural clinic study. Okafor, N. (in press). Okafor, N., & Brandt, K. (2016). Okafor, N., & Lee, J. (2014). Okafor, N., & Lee, J. (2020). Okafor, N., Lee, J., & Adams, R. (2019). Okafor, T. (2012).
The 2021 works take their letters from their titles, and Access comes before rural because The is skipped. Okafor and Brandt (2016) comes before Okafor and Lee (2014), because the second author decides the order before the year does. The two-author entries with Lee come before the three-author entry, because the nothing-precedes-something rule applies to the third author too.
For how to format each of these entries, see our APA 7 citation guide.
Works cited alphabetical order in MLA
MLA also uses the same basics for works cited alphabetical order except that several works by one author are listed by title. The author's name is written in the first entry and replaced by three hyphens and a period in subsequent entries.
Lindqvist, Maja. Coastal Towns after the Mills. Brightwater Press, 2019. ---. The Harbor Strike. Brightwater Press, 2015. ---. A Map of Small Rivers. Kestrel House, 2022. Lindqvist, Maja, and Paul Herrera. Fishing Rights in Practice. Kestrel House, 2017.
The and A are skipped, so Coastal, Harbor and Map decide the order and the 2015 book is second. The book written by Lindqvist with a coauthor is after her single-author books. Several of Lindqvist's coauthored books sort by the coauthor's surname.
MLA has no a and b letters after the year. Its in-text citations add a short title when you cite two works by the same author, so the list needs no extra marks. MLA sorts two different authors with the same surname by first name.
Our MLA 9 citation guide covers the format of each works cited entry.
Chicago bibliography alphabetical order
Alphabetical order for Chicago bibliographies depends on which of the two Chicago systems you use. Notes and bibliography style lists several works by one author in order of title (skipping A, An and The, as in MLA). Author-date style sorts them in order of year (adding a, b and c to works from the same year, as in APA).
Two other rules about Chicago ordering apply in both systems. An entry by an author alone goes before entries where that author is the first of several. Entries that share only the first author are sorted by the coauthors' surnames, however many coauthors there are. Our Chicago 17 citation guide shows the entry format for both systems.
Most differences come down to repeated authors:
| Ordering question | APA 7 | MLA 9 | Chicago 17 bibliography |
|---|---|---|---|
| Two identical surnames | By initials | By first name | By first name |
| Several works by one author | By year, oldest first | By title | By title |
| Same author, same year | By title, then a and b after the year | By title | By title |
| Author alone and with coauthors | Alone first, then by second author | Alone first, then by coauthor | Alone first, then by coauthors |
| No author | By title, skipping A, An, The | By title, skipping A, An, The | By title, skipping A, An, The |
| Filing system | Letter by letter | Letter by letter | Letter by letter or word by word |
How to alphabetize references with no author or a group author
To alphabetize references with no author, file each entry by the first word of its title after any A, An or The. A guide to campus housing goes under G. All three styles start such an entry with the title.
If a work is signed Anonymous, use Anonymous as the author and file under A.
A group author, such as an agency or an association, is written out in full and filed by its name. In APA, American Psychological Association goes under A, spelled out in full. MLA differs in one case: when an organization is both the author and the publisher, MLA starts the entry with the title. The organization appears only as publisher, and the entry is filed by its title.
A title with a number is filed by your manual's rule. Some manuals file the number as if it were spelled out, placing 100 years of rural schools under O. Others put numerals before the letters. Follow APA 7 chapter 9, the MLA Handbook's works cited chapter or Chicago 17 chapter 16, and stick to one choice for the whole list. Start with any instructions from your instructor or journal.
Sort your reference list in one click
Paste your list in any layout. The free Reference Alphabetizer orders it by the rules APA, MLA, Harvard and Chicago share and can remove exact duplicates. No account needed.
Alphabetize my referencesLetter-by-letter vs word-by-word alphabetizing
Letter-by-letter vs word-by-word alphabetizing gives different results when a surname has two parts. Letter by letter ignores spaces, hyphens and apostrophes and compares the letters up to the comma. Word by word stops at the end of the first word. A short first word then comes before any longer word with the same opening letters.
| Letter by letter | Word by word |
|---|---|
| Deacon, R. | De Luca, M. |
| De Luca, M. | Deacon, R. |
| Vance, B. | van Dijk, A. |
| van Dijk, A. | Vance, B. |
APA and MLA file letter by letter. Chicago describes both systems in its index chapter (chapter 16) and applies the same rules to bibliographies. Pick the one your publisher or department names and use it for the whole list.
Mc, Mac and St.
File Mc and Mac exactly as they are spelled. MacLeod and MacNeil come before McAllister, because "ma" comes before "mc". APA, MLA and Chicago all treat these names this way. St. is filed as written, as the letters S and t, unless your department says otherwise, so St. Clair comes after Stack and before Stein.
Apostrophes are ignored in letter-by-letter order. Oakley comes before O'Connor, because "oa" comes before "oc".
Prefixes: van, de, von and al-
Write the surname the way the author writes it in their own publications, and file it by its first letter as written. If an author publishes as van Dijk, A., the entry goes under V in APA, after Vance. Chicago's index chapter sets out the customs for Dutch, French, German, Spanish, Arabic and other names, and some particles are left out of the filing. Chicago files al-Rashid under R, for example. The MLA Handbook has its own guidance on names in other languages. When you're unsure, check how a library catalog lists the author.
Hyphenated and two-part surnames
A hyphenated or two-part surname is one surname, filed under its first part as the author writes it. Nothing precedes something still applies, so Hall, T. comes before Hall-Ward, A. In letter-by-letter order the hyphen is ignored, so Hallam comes before Hall-Ward ("halla" before "hallw"). For a Spanish double surname such as López Ortega, file under the first surname unless the author publishes under the second.
How to sort a reference list with the free Reference Alphabetizer
The free Reference Alphabetizer is an alphabetical order generator built for reference lists. Paste your list in any layout. One entry per line, a numbered list, blank lines between entries and a hanging-indent block copied from Word or a PDF all work. It removes old numbering before sorting.
There's no style setting. The alphabetizer follows rules APA, MLA, Harvard and Chicago have in common. It sorts by the first author's surname, files accented letters with their base letter (Álvarez under A) and files organization names as written. It skips a leading A, An or The on title-first entries. Solo works by an author come first, oldest year first, followed by coauthored works by that author in order of the coauthors' names.
The two options are Remove exact duplicates (on by default) and Number the sorted list. The result line counts duplicates removed. It runs in your browser, free and unlimited, with no account.
Check these entries by hand after sorting:
| Entry type | What the alphabetizer does | What to do |
|---|---|---|
| Several works by one author, in MLA or a Chicago bibliography | Orders them by year | Put them in title order |
| Same author, same year, before letters are added | Orders them by the full title, articles included | Skip A, An and The, then add a and b |
| Years with letters (2021a), n.d. and in press | Places them after the author's other dated works | Put n.d. first, lettered years in year order and in press last |
| Surnames with a space, hyphen, apostrophe or St. | Treats the break as the end of a word | Check each one against your style's filing rule |
| Titles that start with a numeral | Files digits before A | Place them where your manual puts numerals |
If your list contains citations in more than one style, use the free citation generator to rebuild the odd entries before you sort. It rebuilds a reference from Crossref metadata in APA, MLA, Chicago, Harvard, IEEE or Vancouver.
What to check after sorting
Sorting puts all duplicates together. Read the sorted list from top to bottom once.
The alphabetizer removes entries that are identical apart from spacing and capital letters. If two versions of the same paper have slightly different details, they remain in the list, side by side. You can tell which is correct by running them through the AI Citation Checker. It compares your entry against Crossref and Semantic Scholar and displays the record it finds there alongside your own entry. You get a corrected reference to copy.
Each source cited in the text needs an entry. Each entry needs a citation. Go through the paper citation by citation and tick each entry off the sorted list. When you find an entry without a tick, give it a citation, or it comes out.
The result is plain text. Paste it back, restore the italics if necessary, and apply the hanging indent used in your style (0.5 inch in APA and MLA).
Our AI proofreader can also check grammar and clarity in the rest of the paper using tracked changes. It also keeps APA, MLA and Chicago citation formats.
Frequently asked questions
Q: How do I order two references by the same author in the same year in APA?
Sort them alphabetically by title. Skip A, An or The. Add a and b after the year in this order, like (2021a) and (2021b). Use the same letters in your in-text citations, such as (Okafor, 2021a). The rule applies only if the authors and their order are identical in both entries.
Q: Do you alphabetize a reference list by first name or last name?
By last name. The position is decided by the first author's surname. Initials (APA) or first names (MLA and Chicago) only matter when two surnames are identical. Names of coauthors only matter when entries have the same first author.
Q: Should a reference list be in alphabetical order or in citation order?
APA, MLA, Chicago and Harvard lists are alphabetical. IEEE and Vancouver are numbered styles, and their lists follow the order in which sources are first cited in the text. Follow the journal if its author guidelines need something different.
Q: Do you ignore "The" when alphabetizing references?
Yes, at the beginning of a title. When the title stands in for the author, skip A, An and The. When ordering the works of one author by title (MLA or Chicago), skip A, An and The. If there are any words following this in the title, they'll be filed as entered.
Paste up to 100 references and check that each one is a real publication, matched against Crossref and Semantic Scholar, with a corrected reference whenever a record is found.
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