Writing & MediaFree
Acronym and Jargon Checker for Documents
Paste a report, proposal or policy and get every unexplained acronym and insider term flagged where it first appears, plus a ready acronym list.
River's acronym and jargon checker reads your document the way a newcomer would and lists every term that might stop them. Each unexplained acronym comes back with what it stands for, where it first appears, and whether the document ever defines it. Insider phrases such as onboarding funnel or run rate come back with a plain-language alternative. You also get an alphabetical acronym list, ready to paste at the front of a report, thesis or grant application, so no reader has to guess.
A spell checker cannot do this, because every one of these terms is spelled correctly. The problems are about order and audience: an acronym used on page two but defined on page nine, one defined twice in two different ways, or one used only once, where spelling it out would be shorter. The checker flags each case and leaves your text alone. For a whole documentation set, the documentation audit is the bigger job.
This is for anyone writing for readers outside their own team: grant writers, consultants, policy and compliance staff, researchers finishing a thesis, and product people writing for customers. Choose who will read it, the general public, colleagues in other teams or specialists in your field, and the bar for what needs explaining moves with that choice. If your team keeps arguing over which word to use, the terminology and glossary template settles the approved term.
The first-use rule, and when to break it
The standard rule is simple. The GOV.UK style guide puts it this way: the first time you use an abbreviation on a page, explain it in full, then use the initials for the rest of the page. It also lists abbreviations its readers already know, such as UK, EU, VAT and NHS, which need no explanation at all. The lesson travels well: what needs defining depends on who is reading, not on the term itself.
Defining a term is not always the best fix. If an acronym appears once, spell it out and drop the letters, because the reader gains nothing from learning an abbreviation they will never see again. If a document carries a dozen acronyms, readers end up flipping back to the list to decode sentences, so replacing some with short plain names often reads better. The fund is easier to hold in mind than a string of capitals on its fortieth appearance.
Here is an illustrative example. A grant report uses MOU on page one but defines it as memorandum of understanding on page four, uses PI for principal investigator throughout without ever defining it, and mentions a logic model as if every reviewer uses one. The checker lists all three: move the MOU definition to page one, define PI at first use, and add half a sentence explaining the logic model. If a funder turns the report down anyway, the grant rejection review reads the reviewer comments.
How it works
Paste your document
Paste the text or drop in the file, and pick who will be reading it.
River reads it through
Every acronym and insider term is checked against where, and whether, the document explains it.
Get the findings
A table of terms with locations and suggested fixes, plus an acronym list ready to paste.
Fix it in chat
Ask River to rewrite the flagged sentences, or check the next chapter against the same list.
What you get
- Every acronym listed with its meaning, where it first appears, and whether it is ever defined
- Acronyms used before their definition, defined twice, or defined two different ways, each flagged
- Insider jargon paired with a plain-language alternative suited to the reader you chose
- Acronyms used only once marked for spelling out, since the abbreviation adds nothing there
- An alphabetical acronym list, ready to paste at the front of a report or thesis
- Your document left exactly as written, so every change stays your own decision
Common questions
Which acronyms do not need defining?
Ones your readers already know. GOV.UK's style guide, for example, lets writers skip explaining UK, EU, VAT and about twenty others. The checker uses the reader you pick: for the general public it flags almost everything, while for specialists in your field it leaves standard terms of that field alone and says which ones it skipped.
Will it change my document?
No. River reads your document and writes its findings into a separate report: the term, where it first appears, and the suggested fix. Your text stays exactly as you wrote it. If you want the fixes applied, ask in chat afterwards and River will rewrite the flagged sentences so you can review each one before using it.
Does it work on long documents like a thesis?
Yes. Paste the text or drop in the file, whether it is a Word document, a PDF or plain text. For a very long document River says if it stopped partway and where, and you can ask it to continue from there with the same acronym list, so definitions are still checked against the whole text.
What counts as jargon?
Any word or phrase that means something specific inside a team or field but not to an outsider, such as run rate, onboarding funnel or stakeholder alignment. The checker flags these only when your chosen reader is unlikely to know them, and offers a plainer phrase. Technical words with no simpler substitute get a short definition instead.
Can it build the acronym list for my thesis or report?
Yes. The report ends with every acronym in alphabetical order with its full form, as a two-column list you can paste into a list of abbreviations. Check it against your institution's or funder's rules, since some want only terms used more than once and others want page numbers. Ask in chat and River will adjust it.
Is this the same as a readability score?
No. Readability formulas count sentence and word length, so an acronym like CMS scores as one short, easy word even when the reader has no idea what it means. This checker looks at meaning and order instead: whether each term is explained before it is needed, and whether this reader needs it explained at all.
Built by
Chandler Supple
Co-founder & CEO, River
Chandler has spent the last six years working in AI, building tools for millions of users and Fortune 100 companies. In 2025, he co-founded River to build a new kind of operating system for AI agents.
Acronym and Jargon Checker for Documents
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