For writers polishing a draft
Line Editor: Tighten a Page in Your Voice
Paste a page and this AI line editor cuts the filler, keeps your voice, marks every change and gives you a clean copy.
Free to start. No card needed.
How to line edit your own pages
Save the line edit for scenes that will stay, starting where readers drift: the opening pages, long description, any scene a beta reader skimmed. Read the page aloud, or have your computer read it to you, and mark each place you stumble. A sentence that trips you will trip a reader. Then take your time: professionals line edit just 5 to 9.5 pages of fiction an hour, the median range in the Editorial Freelancers Association's 2026 rate chart1.
Cut before you rewrite, beginning with the words that only delay a sentence. Filter words (saw, felt, realized) hold the reader one step back from the scene, so "She saw that the door was open" becomes "The door was open." Qualifiers like really, very and somewhat, stacked adjectives, doubled phrases like "nodded his head" and openers like "There was" usually go next. Crime novelist Elmore Leonard's rules2 are blunt: carry dialogue with "said," never add an adverb to "said," and never write "suddenly."
Next, fix any sentence a reader would have to read twice, such as a "she" that could mean two women. Then vary the rhythm where sentences run together: a short line after two long ones lands harder. Protect what's deliberate (a word repeated for effect, a fragment that marks a beat, a character's own grammar), and when in doubt, keep the version that sounds like you. To catch the pet words you lean on, try the repetitive word finder.
How it works
What is a line edit?
A line edit improves your prose sentence by sentence while leaving the story alone. Writer Beware, an authors' watchdog hosted by the Science Fiction & Fantasy Writers Association, describes it as editing at the sentence level3 for "a smooth prose flow." River's AI line editor does that for a page or scene, up to about 3,000 words at a time. You get every cut struck through, every addition in bold, a clean copy and a one-line reason for each main change.
Paste the page or drop in the file, and pick "Just a light touch," "Tighten it" (the default) or "Cut it hard." River cuts first: filler, filter words, empty intensifiers, hedges and cluttered dialogue tags. Only then does it fix unclear sentences, and it adds no new sentences, ideas or description. Your plot, point of view, tense, dialect, deliberate fragments, spelling and what characters say all stay, and River edits a copy, so your file is left as it was.
River marks every change because AI edits need a careful reader. Iris Marsh, an editor who sells line edits, trained a custom GPT on her past edits and found that it often overedits4. Accept every change, she warns, and your prose might end up flatter or more generic. If a chapter still needs structural work, get notes from the AI book editor first, and run the self-editing checklist on every chapter before you send it out.
How it works
From baggy page to tight page
Paste your page
Paste a page or scene, or drop in the file, then choose how hard River should cut.
River tightens it
It cuts filler, hedges and filter words first, then fixes unclear sentences, keeping your story and dialogue.
See every change
Your doc shows cuts struck through and additions in bold, then the clean, tighter copy.
Take what you like
Keep the edits you agree with, ask River to cut harder or go lighter, then copy the clean page over.
The rain had not let up since Tuesday. Mrs. Ocampo, who was stubborn, kept the shop open anyway, and she kept the lamps lit and the kettle on, almost as if she believed that customers might somehow lamps lit, kettle on, as if customers might wash in with the weather. But as it turned out, in the end, no one actually came. No one came.
- Cut "who was stubborn": the open shop already shows it.
- Folded the list so the sentence keeps moving.
- Three fillers cut. The short line lands harder.
What you'll get
Your page, tighter, with every cut and addition marked
- Your page with cuts struck through and additions in bold
- A clean, tighter copy ready to paste back into your draft
- The main changes, each with a one-line reason
Before and after
Same story, same voice, fewer words.
Jonah slowly walked down the long, narrow hallway, and he could feel his heart beating really fast in his chest. He suddenly realized that the door at the very end of the hallway was slightly open, which was strange, because he was absolutely sure that he had locked it before he left that morning.
Jonah walked down the long, narrow hallway, his heart beating fast. The door at the end was slightly open, which was strange, because he was sure he had locked it before he left that morning. Cut the filter phrases "he could feel" and "He suddenly realized that," so the heartbeat and the open door reach the reader directly. Cut "slowly," "really," "very" and "absolutely," which add little, and "in his chest," which goes without saying. 54 words to 35.
Your sentences, minus the words they didn't need.
What lands in your doc
What's in your line edit
- Your page marked up, with every cut struck through and every added word in bold
- A clean, tighter copy of the same page, ready to paste back into your draft
- Three to eight main changes, each with a one-line reason, such as cutting a hedge or filter word
- A word count before and after, so you can see exactly how much tighter it got
- Your voice kept: what characters say, dialect, slang, deliberate fragments and your spelling stay as written
- Your choice of a light touch, a firm tighten, or a hard cut when you're over length
Questions authors ask
Common questions
What is line editing?
Line editing is a sentence-level edit for style: it makes prose clearer, tighter and smoother without changing the story. A line editor works on word choice, sentence structure, rhythm and dialogue, and cuts whatever slows the reader. It comes after a developmental edit settles the structure, and before copyediting and proofreading catch errors.
What's the difference between line editing and copyediting?
Line editing asks whether a sentence reads well; copyediting asks whether it's correct. Writer Beware describes copyediting as work on the mechanics of writing3, such as grammar, spelling, punctuation, usage, logic lapses and continuity. Some editors do both in one pass and some sell them separately, so check which one a quote covers.
How much does line editing cost?
A line edit of an 80,000-word novel typically costs $2,160 to $2,800. That's 2.7¢ to 3.5¢ a word, the median range for fiction in the Editorial Freelancers Association's 2026 rate chart1. Memoir runs 3¢ to 4¢ and nonfiction 3.5¢ to 5¢. Ask for a sample first: Writer Beware notes that some editors will edit your first few pages free3. Our types of editing guide compares every stage's rates.
Can an AI line editor keep my voice?
It can, if it cuts more than it rewrites and shows you every change. River's editor keeps your plot, dialect, deliberate fragments and spelling, adds no new sentences, and may barely change a page that's already tight. Every cut is struck through and every addition is in bold, so you can restore your own words anywhere. If a passage needs rewriting rather than trimming, use the story rewriter.
How do I line edit a page with River?
Paste a page or scene into the box at the top of this page, or drop in the file, and choose how hard to cut. River writes the marked-up page, a clean copy and the main changes into your free River workspace. It edits up to about 3,000 words in one pass and says where it stopped; say keep going and it carries on.
Do I have to tell Amazon KDP I used AI to edit?
No. KDP's content guidelines5 call text you wrote yourself and then edited, refined or error-checked with AI tools "AI-assisted," and you don't have to disclose it. Only AI-generated content, which an AI tool created, must be declared. You're still responsible for the book meeting KDP's guidelines, and a publisher may have its own AI rules.
Is the AI line editor free?
Yes, it is free to start, and you don't need a card. Your line edit opens in a River workspace, where you can edit it, share it or ask River to change it. Paid plans add more AI use and access to the most advanced models.
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