Free tool · runs in your browser
AI Writing Checker
Paste an email, post or page and see the habits that make writing sound generic: stock AI words, a question opener, "In conclusion" endings, bullets of the same length and sentences all the same size. It is a style checker, not an AI detector. Free, no sign-up, and your text stays in your browser.
Paste your writing to check it
Paste some writing above, or try a sample, to see what stands out.
Eight checks run as you type. Nothing is scored out of 100: each one just shows what it found.
The checks
Your text, marked up
Rewrite prompt
Paste this into ChatGPT, Claude or Gemini. It lists only what was found in your text and tells the AI to keep every fact.
Nothing was flagged, so there is nothing to ask an AI to fix. Read it aloud once; if a sentence trips you, it will trip your reader.
Writing rules for any prompt
Add this block to a prompt before the AI writes, so the first draft avoids these habits. It follows the style target you picked.
What the eight checks look for
None of these is a mistake. They are patterns that show up when a text is written on autopilot, by a person or a model, and each one is easy to fix once you can see it. The checker marks the exact words so you do not have to hunt.
| Check | Why readers notice it | What to do |
|---|---|---|
| Stock words and phrases | The same few words ("seamless", "robust", "unlock") turn up in generic copy, so readers learn to skim past them. | Say the specific thing: what is smooth, what is strong, what you get. |
| Question opener | A question as the first line delays the answer and is the most common opening in generic posts. | Open with the point, then add the detail. |
| Stock closing | "In conclusion" and "Ultimately" announce a summary the reader just finished reading. | End on the last real point or the next step. |
| Sentence length | When every sentence is long and similar, the text has no beat and the main point gets lost. | Mix short and long. Keep the most important sentence short. |
| Same-length bullets | Bullets that all run three words look generated: real points are uneven. | Let each bullet be as long as its point. |
| Lists of three | An "A, B and C" list in every paragraph is a pattern readers notice quickly. | Use the number of items that is true. |
| Repeated openings | Three sentences in a row starting with "We" or "It" read like a template. | Start one with the detail, the time or the person. |
| "Not just X, but Y" | It sets up a claim nobody made in order to knock it down. | State the Y plainly. |
The em-dash count is shown as information only. It never counts as a problem on its own.
Words on the watch list, and what to say instead
The list has 34 entries. A match means "reread this sentence", not "wrong": a nurse can write "critical care" and an engineer can write "dynamic range".
| Word or phrase | Try instead |
|---|---|
delve | look at, dig into |
dynamic | say what actually changes |
landscape | field, market, industry |
testament | proof, sign |
beacon | example, guide |
bespoke | custom, made to order |
game-changer | say what changed and by how much |
seamless | smooth, easy |
unlock | get, open, use |
elevate | improve, raise |
robust | strong, reliable |
tapestry | mix |
critical | key, or say why it matters |
foster | build, encourage |
pivotal | key, main |
hassle-free | easy |
revolutionize | change (and say how) |
ever-evolving | changing |
in today's fast-paced | start with the point |
it's important to note | cut it and say the thing |
leverage | use |
realm | area, field |
cutting-edge | new (and name what is new) |
unleash | use, release |
streamline | simplify |
multifaceted | say which sides |
holistic | whole, complete |
synergy | working together |
paradigm shift | big change |
navigate the complexities | deal with |
embark on a journey | start |
plays a crucial role | say what it does |
at the end of the day | cut it |
when it comes to | for, with |
Using the rewrite prompt
- Paste your text and read the marked-up version. Fix what you agree with by hand; that is usually the best edit.
- For the rest, press Copy prompt and paste it into ChatGPT, Claude or Gemini. Your text is already inside it.
- Read the AI's list of changes. If it changed a fact or a number, undo that part. The prompt tells it not to, but always check.
- Running the checker on the new version shows whether the habits are gone or only moved.
Writing something new? Copy the Writing rules block into your prompt first. Prompts that name a role, set rules and ask for a self-check work better than "make it sound human"; the Prompt Analyzer scores your prompt on those points, and our guide on how to write AI prompts explains them.
What this tool will not do
It does not detect AI, it does not rate quality, and it cannot tell whether your facts are right. Detectors that claim to know who wrote a text are often wrong in both directions, so this page does not play that game. Use it the way an editor would: to find the sentences worth a second look. If your school, publisher or workplace has a rule about AI use, follow that rule whatever the checker says.
Related free tools and prompts
Prompt Analyzer
Score the prompt you give the AI: task, context, format, limits and details.
Open Analyzer →Prompt Optimizer
Turn a rough request into a structured prompt before the AI writes.
Open Optimizer →Prompt Doctor
Find what a writing, image or video prompt is missing and get a fixed version.
Open Doctor →Looking for ready-made writing prompts? Browse the chat and writing prompts, the ChatGPT prompts or the Claude prompts.
Questions, answered
Is this an AI detector?
No. It checks writing habits (stock words, openings, closings, sentence rhythm) and never says who or what wrote the text. AI detectors guess at authorship and are known to be unreliable, and this tool makes no such guess.
Will fixing these things get my text past an AI detector?
There is no promise of that and the tool is not built for it. Fixing these habits makes writing clearer and more specific for a reader. If a school, publisher or employer limits AI use, follow that rule; changing the style of a text does not change how it was made.
Why is my own writing flagged?
People use these words and shapes too. A match only marks a sentence worth rereading. "Critical care", "a dynamic range" and a list of three real items are all fine. Keep what you chose on purpose.
Is my text sent to PromptUp or an AI company?
No. The checks run in your browser with fixed rules, and the text is not sent or saved anywhere. The rewrite prompt is only made when you press copy and paste it into an AI app yourself; from that point the app you pick sees the text.
Which style should I pick?
Punchy suits emails and ads: about 80% of sentences under 13 words. Balanced suits blog posts and web pages at about 60%. Long-form suits essays and reports at about 40%. The only thing the choice changes is the sentence-length target.
Can I use the rewrite prompt in ChatGPT, Claude or Gemini?
Yes. It is plain text that works in any of them. It lists only what was found in your text, tells the AI to keep every fact, and asks for a short list of changes so you can see what moved.