Instant Key Point Detection
Ranked results appear as fast as you can click. Typical paragraphs are analysed in a couple of milliseconds, with no network round trip and no queue.
100% Free • No Sign-Up Required
Find the Important Parts.
Instantly.
Turn long paragraphs into clear, highlighted insights in seconds. Simply paste your text and let KeyGlow do the work.
- Instant results
- Text never leaves your device
- No account needed
Automatic text highlighter
Try an example
Your Text
0 words0 / 50,000 characters
Highlighted Text
Main IdeasImportant FactsDefinitions
Highlighted text
Your highlighted text will appear here. Paste something on the left, or try an example above.
Press Ctrl + Enter to highlight. Nothing is uploaded.
How It Works
Three steps, about ten seconds
No setup, no upload and no waiting on a server. Everything below happens inside your own browser tab.
Paste Your Text
Drop in an article, lecture notes, a report or a single paragraph — up to 50,000 characters. Nothing is uploaded.
Highlight Important Points
Our browser-based algorithm ranks every sentence and marks the main ideas, key facts and definitions it finds.
Study or Share
Adjust the intensity, then copy, download or print your highlighted text and key takeaways.
Features
A proper highlighter, not a summary generator
KeyGlow marks up the text you already have instead of rewriting it, so you keep the author’s exact words — and the context around them.
Automatic Sentence Highlighting
Your original text stays exactly as you wrote it — punctuation, line breaks and capitalisation intact — with the important sentences marked in place.
Facts & Definitions Detection
Statistics, dates and quantities are marked green. Definitions and terminology are marked purple. Central ideas are marked yellow.
Adjustable Highlight Intensity
Move from a light 10% skim to a detailed 60% pass instantly, and switch any highlight category on or off without re-analysing.
Private Browser-Based Processing
Nothing is uploaded. Your text never leaves the tab, so you can safely paste coursework, client documents and unpublished drafts.
Completely Free to Use
No account, no paywall, no credit limit and no watermark. Copy, download or print your highlighted text as often as you like.
Under The Hood
How KeyGlow decides what matters
Four independent signals are combined into a single score for every sentence, then a redundancy filter removes anything that repeats a point already highlighted.
Sentence centrality (TextRank)
Every sentence becomes a node in a graph, connected to the others by how much vocabulary they share. A weighted PageRank then finds the sentences the rest of the text keeps circling back to — the ones carrying the thread of the argument.
Keyword weighting (TF-IDF)
Terms are scored by how often they appear in a sentence against how widely they appear across the whole text. Words that are everywhere, and words that appear once in passing, both get discounted. What remains is the vocabulary that actually distinguishes your material.
Fact and figure detection
Percentages, dates, currency, measurements, quantities and comparative claims such as "three times higher" are detected directly. A number alone never qualifies — the sentence around it has to carry real content too.
Definition detection
Phrasings like "X is defined as", "X refers to", "X means" and "X is a type of Y" are recognised as terminology and marked separately, because a definition is usually the single most useful line on a revision sheet.
An honest limitation
KeyGlow is statistical, not semantic. It has no language model behind it, which is exactly why it is instant, free and private — but it also means it can only infer importance from structure, vocabulary and pattern, not from genuine understanding. On explanatory prose it is reliable. On poetry, dialogue or heavy irony it is not. Treat the highlights as a well-informed first pass, then use your own judgement.
Use Cases
Who is KeyGlow for?
Anyone who has to read more than they have time for.
Students
Turn a dense textbook chapter into a revision sheet. Paste your reading, highlight the definitions and statistics you are expected to remember, then print it for the night before an exam.
Researchers
Triage a stack of abstracts and papers quickly. See at a glance which sources actually contain findings, figures and defined terms, and which ones are background you can skip.
Professionals
Work through reports, policies and long email threads faster. Surface the numbers, deadlines and commitments buried in the middle of a document before you reply.
Writers & Editors
Check whether your own draft lands its point. If the highlighter marks a throwaway aside instead of your thesis, that is a useful signal about where your emphasis actually sits.
FAQ
Frequently asked questions
Is KeyGlow completely free?
Yes. Every feature is free with no account, no trial and no usage limit. The highlighting runs on your own device, so there are no per-request costs to pass on to you. The site is supported by display advertising.
How does automatic highlighting work?
KeyGlow splits your text into sentences, strips out common filler words and scores what remains. It uses a TextRank-style graph to find the sentences most connected to the rest of your text, TF-IDF keyword weighting to find the terms that carry meaning, and pattern matching to spot statistics, dates and definitions. Position, sentence length and discourse markers such as "in conclusion" act as supporting signals, and a redundancy filter stops two sentences that say the same thing from both being highlighted.
Do I need an account?
No. There is no sign-up, no email address and no login. Open the page, paste your text and highlight it.
Is my text private?
Your text is never uploaded. All analysis happens inside your browser tab using JavaScript, so the words you paste are never sent to a server, an API, an analytics tool or an advertiser. Nothing is saved unless you explicitly choose to save a draft on your own device. Advertisements on the page may independently collect technical and usage data according to their own privacy policies, but they have no access to the contents of the editor.
Can I highlight long articles?
Yes, up to 50,000 characters per analysis — roughly 8,000 words, or about thirty pages. Larger inputs are processed on a background thread so the page stays responsive while it works.
Can I download my highlighted text?
Yes. You can copy the highlighted text with its colours intact, copy the key takeaways as a plain list, download a self-contained HTML file, or print a clean study-friendly version straight from your browser.
Does KeyGlow use artificial intelligence?
Not in the large language model sense. KeyGlow uses classical statistical text analysis — graph-based sentence ranking, keyword weighting and pattern detection. That is what keeps it instant, free and private. It means KeyGlow is very good at finding the sentences that carry the most information in your text, but it does not understand meaning the way a human reader does, so treat the highlights as a strong starting point rather than a final judgement.
What kinds of text work best?
Explanatory prose does best: textbook chapters, lecture notes, news articles, research summaries, reports and essays. Poetry, dialogue, song lyrics and bullet lists of single words give weaker results, because the algorithm relies on sentences sharing vocabulary with one another.
About this free text highlighter
KeyGlow is an online text highlighter that reads a passage and marks the sentences most likely to matter. It was built for the moment when you have forty pages of reading, an hour to do it in, and no idea which paragraphs are load-bearing. Paste the text, run the highlighter, and the main ideas, supporting statistics and defined terms separate themselves out by colour.
It is deliberately not a summarizer. A summary replaces the author’s words with new ones, which is useful for a quick gist but lossy and sometimes misleading — and for revision it is close to useless, because the exact phrasing is often what you are being tested on. KeyGlow keeps every word, every line break and every piece of punctuation exactly as you pasted it, and only adds colour on top. You can always read the sentences around a highlight to check the context.
Because the analysis is statistical rather than generative, it runs locally in a few milliseconds and costs nothing to operate. That has a pleasant side effect for privacy: there is no server to send your text to, so coursework, client reports and unpublished drafts stay on your own machine. It also sets an honest expectation — KeyGlow is measuring structure and vocabulary, not comprehending meaning, so it works best on explanatory prose and least well on anything that depends on tone.
Start with the Balanced setting. If a highlight looks wrong, slide the intensity down to see only the strongest candidates, or switch off a category to focus on just the facts or just the definitions. When you are happy with the result, copy it with the colours intact, download it as a self-contained HTML file, or print it as a revision sheet.