AI writing assistant
Fix grammar and spelling, improve emails and change the tone of your text, privately on your device.
Select a PDF file
or drop them anywhere on this page
Processed on your device. Never uploaded.
Your text is checked by the AI built into your browser, on your own device. It is never uploaded or stored.
What should I do?
Your browser is downloading its built-in AI model. Until it is ready, basic fixes are available.
Improving your text…
Processing on your device. Nothing is uploaded.
Paste your text
Paste an email, message, cover letter or any text you wrote.
Choose what to do
Fix mistakes, improve the wording, change the tone, shorten it or draft a reply.
Copy the result
See every change highlighted, then copy the text or keep refining it.
The AI writing assistant corrects grammar, spelling and punctuation, improves the wording of emails and messages, changes the tone to formal or friendly, shortens long text and drafts polite replies. Unlike most online grammar checkers, your text is checked on your own device and is never uploaded.
How to check grammar and improve an email
- Paste your text: an email, a message to a colleague, a cover letter, a post or a report paragraph.
- Choose what to do: Fix grammar & spelling, Improve writing, More formal, More friendly, Shorter or Write a reply.
- Press the button. Every change is highlighted, with additions in green and removals crossed out.
- Copy the result, download it as a text file, or choose Edit this further to keep refining it.
About AI writing assistant
In Chrome and Edge on a computer, the writing assistant uses the AI model built into the browser (such as Gemini Nano in Chrome). It runs entirely on your device, so emails with personal, financial or business details never reach a server, and there is no account, no word limit per day and no subscription.
In other browsers and on phones, Fix grammar & spelling still makes basic corrections on your device: common spelling mistakes, extra or missing spaces, capital letters, “i” on its own and words typed twice. The other tasks need the browser’s built-in AI.
The AI keeps names, numbers, dates, amounts, email addresses and links exactly as you wrote them, and a reply leaves placeholders such as [date] instead of inventing details. Like any AI, it can make mistakes, so read the result before you send it.
When to use it
- Work emailFix mistakes and make an email sound clear and professional before you send it.
- Job applicationsPolish a cover letter or the summary on your CV.
- Writing in a second languageCheck English, Spanish, French or German text you are not sure about.
- Quick repliesDraft a polite answer to an email in seconds, then add your own details.
Why PaperWingPDF
- Private by design
- No queues, no waiting
- Chain your tools
- Works offline, installs as an app
Frequently asked questions
Is my text sent to an AI service?
No. The AI is built into your browser and runs on your device. Your text is never uploaded or stored.
Why can I only use basic fixes?
Full AI help needs the AI model built into Chrome or Edge on a Windows, Mac, Linux or ChromeOS computer. On phones and in other browsers, basic spelling and spacing fixes are available.
Which languages does it support?
The built-in AI works best in English and also supports languages such as Spanish, French, German, Portuguese, Italian, Japanese and Chinese. Basic fixes work in any language, with extra spelling fixes for English.
Is it free?
Yes. There is no account, no daily limit and no watermark, like every PaperWingPDF tool.
Is AI writing assistant free?
Yes. AI writing assistant is free to use, with no sign-up, no watermark and no daily limit.
Are my files uploaded to a server?
No. PaperWingPDF processes your files inside your browser, on your own device. They are never uploaded, and they are cleared from memory when you close the tab.
Does it work on my phone?
Yes. PaperWingPDF works in any modern browser on Windows, Mac, Linux, Android and iPhone, with nothing to install.
Is there a file size limit?
Each file can be up to 300 MB. Very large files depend on your device's memory, so a computer handles them faster than a phone.