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Run-On Sentence Checker

Detect and fix run-on sentences, comma splices, and overly long sentences. Break complex ideas into clear, readable writing.

★★★★★ 4.8/5·Free · No signup·Used by 10K+ writers

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See the Difference

Before

I went to the store and I bought some groceries and then I went home and I started cooking dinner but I realized I forgot to buy onions so I had to go back.

After

I went to the store and bought some groceries. When I got home and started cooking, I realized I forgot onions — so I had to go back.

Before

The project was delayed because the team was waiting for approval from management, the client hadn't sent the final specifications yet, and there were several bugs that needed to be fixed before launch.

After

The project was delayed for several reasons. The team was waiting for management approval, the client hadn't sent final specifications, and several bugs still needed fixing before launch.

Before

She said she would come to the meeting however she didn't show up, we waited for an hour then we decided to start without her.

After

She said she would come to the meeting. However, she didn't show up. After waiting for an hour, we decided to start without her.

How It Works

1
📋

Paste Your Text

Type or paste your text into the editor above. Up to 500 characters in the free tool.

2

AI Processes It

Our AI analyzes your text for improvements and generates a polished version in seconds.

3

Copy & Use

Copy the improved text with one click. Install the extension for unlimited use on every website.

Why Use This Tool

🔍

Detects Run-On Sentences

AI identifies sentences that are too long, have comma splices, or string too many clauses together.

✂️

Smart Sentence Breaking

Breaks long sentences at natural points — using periods, semicolons, and transitional phrases where appropriate.

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Improves Readability

Shorter, well-structured sentences are easier to read and understand, especially for professional communication.

🎓

Great for Academic Writing

Perfect for essays, research papers, and dissertations where sentence clarity is critical.

Who Is This For?

🎓

Students

💼

Professionals

🌍

ESL Speakers

✍️

Content Writers

What Users Say

★★★★★

Finally a tool that understands non-native English! My emails sound so much better now.

🇮🇳

Priya S.

Software Engineer

★★★★★

I use this before every important email. The suggestions are always natural and professional.

🇯🇵

Yuki T.

Product Manager

★★★★★

Way better than Grammarly for my needs. It catches mistakes other tools miss.

🇧🇷

Carlos M.

Marketing Lead

FluentEditor vs Other Tools

FeatureFluentEditorGrammarlyQuillBot
Built for Non-Native Speakers
Free to Use✅ 200/mo❌ 5/day✅ Limited
Catches ESL Patterns
Explains Corrections✅ (Premium)
Chrome Extension
Works on 40+ Sites
No Account Required✅ 5/day
Pattern Tips for Learning

Fix Writing Everywhere

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Frequently Asked Questions

What is a run-on sentence?
A run-on sentence occurs when two or more independent clauses are joined without proper punctuation or conjunctions. For example: "I went home I ate dinner" should be "I went home. I ate dinner." or "I went home, and I ate dinner."
What is a comma splice?
A comma splice is when two independent clauses are joined only by a comma, without a conjunction. For example: "It was raining, we stayed home" should be "It was raining, so we stayed home."
How long is too long for a sentence?
Generally, sentences over 25-30 words become harder to read. This tool identifies sentences that could benefit from being split, but length alone isn't the only factor — complexity matters too.
Is it free?
Yes! Check up to 5 texts per day for free. Create a free account for 200 checks per month.

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