Free Comma Checker
Check comma placement online, with the Oxford comma handled your way. Pick serial comma or not, paste up to 250 words, and get missing, misplaced and unnecessary commas fixed, comma splices repaired, and every correction explained, while your words stay exactly as you wrote them.
Sent to our server only to run this tool; we keep no copy of your text.
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How to check your commas in three steps
Choose your list style
Oxford comma for APA, Chicago and most US academic styles; no Oxford comma for AP and many British house styles. The checker applies your choice consistently to every list.
Paste and check
Up to 250 words per check. Introductory commas, paired commas around nonrestrictive clauses, list punctuation and comma splices are all corrected in one pass.
Review the fixes and copy
Each fix shows your original wording, the correction and the rule applied. Comma splices note the semicolon repair explicitly. Copy the corrected text when you are satisfied.
Why writers use this comma checker
Your serial comma, your call
The one comma rule style guides genuinely disagree on is an explicit toggle, not a hidden assumption. Match APA and Chicago, or AP, in one click.
Splices repaired properly
Two sentences joined by a bare comma get a semicolon, with a note saying so, never a silent rewording of your clauses.
Meaning-bearing commas
Paired commas around nonrestrictive clauses are checked both ways, because in research writing that pair can change the scope of your claim.
Commas only
Words and other punctuation stay untouched, which makes the pass fast to audit and safe to accept.
The comma is the hardest working mark in academic writing
No other punctuation mark does as many jobs as the comma: separating list items, setting off introductions, pairing around asides, and marking the boundary where one clause hands off to the next. That workload is why comma errors dominate the mechanical corrections in academic editing, and why the same writer can punctuate the same construction three different ways in one manuscript, especially in a document written across weeks.
It is also the mark where correctness and style overlap most. The Oxford comma question has no universal answer, only a per-style-guide one, and a checker that silently imposes either choice is making your decision for you. This checker makes the preference explicit, applies it consistently across every list it finds, and keeps the exception every guide agrees on: when omitting the serial comma creates real ambiguity, the comma stays, with a note explaining why. Meanwhile the commas that do carry meaning, the pairs around nonrestrictive clauses, get checked in both directions, because a missing half of that pair quietly changes what your sentence claims.
Commas travel with company. If your draft's issues extend to semicolons, apostrophes and hyphens, the punctuation checker runs the full mark set in one pass, with the same words-are-off-limits rule. And when sentence construction itself is the issue, comma problems are often grammar problems wearing a disguise, which is what the grammar checker is for.
For a full thesis or manuscript, the ProofreaderPro editor applies consistent comma style across the entire document as part of a complete proofread, with tracked changes you approve one by one.
Comma checker FAQs
What is the Oxford comma, and should I use it?
What comma errors does the checker fix?
What is the difference between restrictive and nonrestrictive, and why do the commas matter?
Will the checker change my words or other punctuation?
Commas sorted. Now proofread the whole document.
The ProofreaderPro editor applies consistent punctuation, grammar and academic register across your complete manuscript, with tracked changes you accept or reject line by line. Free to try.
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