Free AI summarizer
Paste a YouTube link, drop a PDF, or paste text and get a clear, sectioned summary in seconds. No signup, no card.
Free to use. Free to keep.
The tool needs no account. A free account saves every result, adds the full study kit, and syncs to your phone.
This free AI summarizer turns a YouTube video, a PDF, or any text into clear, titled sections in seconds. You get the structure of the material, not a wall of prose. No sign up to try it. Sign up free to save the summary and turn it into flashcards and a quiz on the same source.
Give it your source
Paste your notes, a transcript, or an article, paste a YouTube link, upload a PDF, upload a .pptx deck, upload a photo of the page, or paste a link to a public web page. No account needed.
Run the tool
The AI reads your source on our server and writes the result. A long file takes a little longer.
Study or save
Use it right away, or save it to a free library and get the full study kit from the same source.
Why use this ai summarizer
Sectioned, not a blob
The summary comes back as short titled sections, so you can scan the structure and jump to what matters.
Video, PDF, or text
A lecture on YouTube, a reading or slides as a PDF, or text you paste. One summarizer for all three.
Read it or hear it
Switch between sections and a bullet outline, or press Listen and let your browser read it out loud.
Then go deeper
One click turns the same source into flashcards, a quiz, key points, or a mind map, without pasting it again.
Who it's for
Students
Get the shape of a lecture or chapter in a minute, then spend your time on the hard parts.
Researchers
Pull the question, method, and result out of a dense paper before deciding to read it in full.
Content creators
Summarize a long video or article into the key sections you want to cover yourself.
Questions
What can I summarize?
A YouTube video with captions, a PDF (readings or slides), or any text you paste. The summary comes back as short titled sections.
Is the summarizer free?
Yes, no account needed. Sign up free to save summaries and turn them into a full study kit with flashcards and a quiz.
How long can the text be?
Up to about 12,000 characters per run, which covers most lectures and articles. For longer material, sign up to process the whole thing.
Study it on your phone too
Synapsi runs on the web, iPhone, iPad, Mac and Android. One free account, the same notes everywhere.
Related study tools
Got a PDF instead? Pull the text out first, then run any study tool on it.