Free Run-On Sentence Checker
Find and fix run-on sentences, fused sentences, and comma splices for free. Improve sentence boundaries without changing what you meant.
Fixing Run-Ons, Fused Clauses, and Comma Splices
A run-on sentence is not simply a long sentence. In English grammar, a run-on occurs when two or more independent clauses (complete thoughts that could stand alone as separate sentences) are joined together without proper punctuation or coordinating conjunctions.
The two most common forms are fused sentences (where clauses run together with no punctuation at all) and comma splices (where two independent clauses are joined by only a comma without a coordinating conjunction such as and, but, or, so).
Make Text Better analyzes clause boundaries and applies the most natural remedy: inserting appropriate coordinating conjunctions, separating clauses with periods, or connecting closely related ideas with semicolons or subordinating clauses.
The Core Types of Run-On Errors
The Comma Splice
Connecting two complete independent thoughts with just a comma (e.g. "I love writing, it helps me think").
The Fused Sentence
Running two independent clauses together with zero punctuation or conjunction between them.
Excessive Polysyndeton
Stringing four or five clauses together with repetitive "and... and... so..." conjunctions.
Confusing Transition Adverbs with Conjunctions
Using "however", "therefore", or "furthermore" with only a comma instead of a semicolon or period.
Who Benefits From This Tool
- ✓ Students striving for top grades on essays and admissions statements.
- ✓ Writers who write quickly in a stream of consciousness and need boundary cleanup.
- ✓ English language learners mastering independent vs. dependent clause mechanics.
- ✓ Business professionals sending high-stakes emails and proposals.
Why Our Boundary Corrections Are Superior
Rather than mindlessly splitting every long sentence into short staccato fragments, Make Text Better chooses the boundary solution that best maintains your rhetorical rhythm and logical connection.
Real Correction Examples
See how Make Text Better fixes errors and improves natural phrasing while keeping your exact meaning.
I finished the report it was already midnight.
I finished the report, but it was already midnight.
The experiment produced inconclusive results, the team decided to repeat the trial with a larger sample size.
The experiment produced inconclusive results; therefore, the team decided to repeat the trial with a larger sample size.
We arrived at the conference early and the keynote speaker was setting up and the registration desk had not opened yet.
When we arrived at the conference early, the keynote speaker was setting up, but the registration desk had not opened yet.
How to Use This Tool
Paste your draft
Enter any text with suspected run-on sentences or comma splices.
Click Make It Better
The tool audits independent clauses and identifies missing boundaries.
Copy clean, punctuated prose
Receive grammatically bounded sentences with natural flow.
Frequently Asked Questions
Is a long sentence always a run-on sentence? ▼
No! A sentence can be 50 words long and grammatically flawless if its clauses and phrases are properly coordinated and subordinated. A run-on specifically refers to independent clauses joined without correct punctuation or conjunctions.
What is a comma splice? ▼
A comma splice happens when two independent clauses are joined with only a comma (e.g., "The weather was bad, we stayed inside"). It should be corrected with a period, a semicolon, or a coordinating conjunction ("The weather was bad, so we stayed inside").
Will this tool break my sentence into choppy pieces? ▼
No. Where appropriate, it uses semicolons or subordinating conjunctions to preserve the nuance and continuous flow of your thought.
Is this run-on sentence checker free? ▼
Yes, 100% free with no account required.