Seventeen free tools for coursework and everyday study: merge, split and compress PDFs, convert between PDF, Word and images, take the audio from a lecture video, count words, check readability and grammar, build references in APA, MLA or Harvard, and work out your GPA.
The PDF, Word, image and audio tools run inside your browser, so your files are never uploaded. The grammar checker is the one tool that sends text away, to LanguageTool, to be checked.
- Merge PDF Join several PDF files into one, in the order you choose. Open tool
- Split PDF Extract pages or split a PDF into separate files. Open tool
- Compress PDF Make a PDF smaller for email and upload limits. Open tool
- PDF to Image Turn PDF pages into JPG, PNG or WebP images. Open tool
- Images to PDF Combine photos or scans into a single PDF. Open tool
- PDF to Word Convert a PDF into an editable Word (.docx) file. Open tool
- Word to PDF Save a Word (.docx) document as a PDF. Open tool
- MP4 to MP3 Extract the audio from a video as an MP3 file. Open tool
- Image Compressor Shrink and resize photos without visible quality loss. Open tool
- Image Converter Convert images between JPG, PNG and WebP. Open tool
- Word Counter Words, characters, sentences, reading time and keywords. Open tool
- Citation Generator References in APA 7, MLA 9 and Harvard style. Open tool
- GPA Calculator Semester and cumulative GPA, or percentage from marks. Open tool
- QR Code Generator QR codes for links, Wi-Fi, email and phone numbers. Open tool
- AI Writing Checker Estimate whether text reads as AI-generated. Up to 5,000 words. Open tool
- Readability Checker Readability scores with long sentences and passive voice highlighted. Open tool
- Grammar & Spelling Checker Find grammar, spelling and punctuation mistakes. Open tool
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Why your files stay on your device
Most online converters upload your file to their server, process it there and send it back. These tools do the work in the page itself, using open-source libraries such as pdf-lib, PDF.js and a JavaScript MP3 encoder. That keeps assignments, transcripts and scanned IDs off other people’s servers, and there is no queue or daily limit. The trade-off is that very large files depend on your device’s memory, so a phone will struggle sooner than a laptop.
A note on the AI writing checker
The AI writing checker gives an estimate, not proof. Like every detector, free or paid, it sometimes flags human writing, especially formal technical writing and work by people writing in a second language. It should never be the only reason to question someone’s work. Its page explains exactly how the score is worked out.
Tools by topic
PDF tools
Images & media
Writing & study
- Word Counter
- Citation Generator
- GPA Calculator
- AI Writing Checker
- Readability Checker
- Grammar & Spelling Checker
Questions people ask
Are these tools free?
Yes. There is no account, watermark or daily limit. The grammar checker relies on a free service that allows a few checks a minute, so wait a moment if it says it is busy.
Is it safe to use them with confidential documents?
The PDF, Word, image and audio tools never upload your files; they are processed in your browser and the results are saved straight to your device. The grammar checker sends the text you paste to LanguageTool for checking, so leave out anything you are not allowed to share.
Do they work on a phone?
Yes, in current versions of Chrome, Safari, Edge and Firefox. Big PDFs and long videos take longer on a phone and can run out of memory, so use a laptop for those.
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