Abbreviation & Acronym Checker
Paste a paper or thesis chapter and every abbreviation is checked against APA's guidance: defined at first use, used often enough to earn its place, and never swapped back for the full term. The defined ones are gathered into an alphabetized List of Abbreviations you can paste straight into your front matter.
Separate with commas. Add the ones your readers know without a definition.
Paste your text to check its abbreviations.
How to Use the Abbreviation & Acronym Checker
- Paste your text. A chapter or a whole paper. The reference list is ignored by default, since group-author names are written out in full there.
- Tell the checker what to skip. Abbreviations APA lets you leave undefined are skipped automatically; type any others your readers already know — UK, PhD, DNA — into the ignore box.
- Work through the table. Abbreviations appear in the order you first use them, each with its definition, its count of uses, and a note for every problem found.
- Copy the List of Abbreviations. Copying pastes a two-column table into Word or Google Docs, and the CSV opens in any spreadsheet.
What the Checker Looks For
Here an abbreviation is a word with at least two capital letters that make up at least half its letters: RT, NGO, fMRI, and mRNA qualify; McDonald and iPhone do not. Digits and hyphens stay attached, so COVID-19 and SARS-CoV-2 are single abbreviations, and a plural s is folded in, so NGOs counts as a use of NGO. Lines written entirely in capitals are skipped as headings, Roman numerals such as the II in World War II are skipped unless you define them, and a unit symbol after a number (5 GB) is read as a measurement.
Definitions are found in either order — response time (RT) or RT (response time) — and in the square brackets APA uses inside parentheses, as in (World Health Organization [WHO], 2020). To work out which words an abbreviation stands for, the checker uses Schwartz and Hearst's 2003 algorithm: it walks the abbreviation's letters from right to left through the words before the parenthesis, and its first letter must begin a word.
The Rules Each Abbreviation Is Checked Against
| Flag | What it means | APA guidance |
|---|---|---|
| Never defined | No definition anywhere in the text. | Define every abbreviation except dictionary words, statistical symbols, units, and Latin abbreviations. |
| Used before it is defined | The abbreviation appears earlier than its definition. | Write out the full term the first time, with the abbreviation after it in parentheses. |
| Defined more than once | Two or more definitions. | Define it once in the body; a part that must stand alone, such as an abstract or a table note, may define it again. |
| Used fewer than three times | Fewer than three uses after the definition. | Use an abbreviation at least three times or write the term out, unless it is a standard abbreviation for a long, familiar term. |
| Spelled out again | The full term reappears after the definition. | Use abbreviations consistently; do not switch between an abbreviation and the term it stands for. |
Source: APA Style Abbreviations Guide (2022). The checker counts uses after the definition, which is the stricter reading of “at least three times.”
Worked Example
Choose Try a sample to load a short abstract and method section. RT is defined as response time and used four more times, so it passes. WM is defined, then used only twice and spelled out again as working memory, so it collects two flags. EEG is never defined. ANOVA appears before its definition and is never used after it. The List of Abbreviations gathers the four defined terms — ANOVA, NGO, RT, and WM — in alphabetical order, with response time in lowercase because its capital only marked the start of a sentence.
When Not to Abbreviate
APA's advice is to abbreviate sparingly — only when an abbreviation is familiar to your readers or saves genuine repetition. A term you use twice is clearer written out. Abbreviations entered as words in the dictionary need no definition (APA's examples are AIDS and IQ), and neither do statistical symbols such as M, SD, and OR or a unit after a number (80 m, 30 min). Other statistical abbreviations — ANOVA, CI, RMSEA — must be defined. Latin abbreviations such as e.g. and i.e. are never defined; APA keeps them inside parentheses.
- Abbreviations with fewer than two capitals are not checked. Forms such as km, kHz, and pH are invisible to the checker — units and symbols seldom need a definition anyway.
- Unusual definitions can be missed. “RT, which stands for response time” is not recognized; use the parenthesis form APA prescribes.
- Some flags call for judgment. APA itself allows a standard abbreviation for a long, familiar term to appear fewer than three times.
- Words in capitals can look like abbreviations. An all-capital word used for emphasis is reported as undefined; add it to the ignore box.
Frequently Asked Questions
- How do you define an abbreviation in APA Style?
- Write the full term the first time it appears and put the abbreviation in parentheses after it: response time (RT). If the term is already inside parentheses, use square brackets for the abbreviation instead: (response time [RT]). After that, use the abbreviation alone.
- How many times should an abbreviation be used?
- APA's guideline is at least three times in a paper; if you would use it only once or twice, write the term out each time so readers do not have to remember what it means. A standard abbreviation for a long, familiar term is the exception and can be clearer even when used less.
- Which abbreviations do not need to be defined?
- In APA Style: abbreviations listed as words in the dictionary (such as AIDS and IQ), symbols for statistics (M, SD, df, p, OR), units of measurement and time used with a number, and Latin abbreviations such as e.g., i.e., and et al. Everything else is defined at first use.
- What is a List of Abbreviations, and do I need one?
- It is an alphabetized two-column table of every abbreviation in a thesis or report and what it stands for, placed in the front matter. Many graduate schools require one for theses and dissertations; check your institution's formatting guide for where it goes and how it should look.
- What is the difference between an acronym and an initialism?
- An acronym is pronounced as a word (NATO, laser), an initialism letter by letter (FBI, RT). APA calls both abbreviations and applies the same rules to each, and so does this checker.
- How are plural abbreviations handled?
- A plural adds a lowercase s with no apostrophe — NGOs, not NGO's — and the checker counts NGOs as a use of NGO. When the definition itself is plural, as in non-governmental organizations (NGOs), the List of Abbreviations keeps the wording you wrote.
- Is my text uploaded anywhere?
- No. The checking runs entirely in your browser; your paper is never sent to a server or stored.