What This Tool Does
Text Summarizer is a free browser tool that creates extractive summaries from pasted text. It scores sentences with TF-IDF word importance, adds small position bonuses, selects the top sentences for Short 20%, Medium 35%, Long 50%, or a custom N-sentence summary, and highlights the chosen sentences in the original text.
Inputs Explained
- Text: Paste the article, notes, report, essay, transcript, or briefing you want to summarize.
- Summary length: Choose Short 20%, Medium 35%, Long 50%, or N sentences for a fixed sentence count.
- Custom sentences: Enter the exact number of sentences to keep when the custom option is selected.
- Summarize: Runs the local TF-IDF scoring engine and updates the summary and highlighted original.
- Stats: Shows original word count, summary word count, and reduction percentage.
How It Works
The summarizer splits the text into sentences, tokenizes each sentence, lowercases words, removes a built-in stopword list, and calculates term frequency and inverse document frequency across sentences. Each sentence receives a score from its TF-IDF terms plus a 0.2 bonus for the first and last sentence. The highest-scoring sentences are selected, then returned in their original order so the summary remains readable.
Formula / Logic Used
Text Summarizer
Summarize pasted text locally with TF-IDF scoring, position bonuses, and highlighted source sentences.
Summary
Highlighted Original
Step-by-Step Example
Sample input: A six-sentence article about extractive summarization.
Sample output: Medium 35% keeps about two top-scored sentences, ordered the way they appeared in the original text.
Explanation: Sentences with distinctive terms such as summarization, extractive, TF-IDF, and position score higher than generic sentences. The highlighted original shows exactly which source sentences were selected.
How to read the result: Use the output from Text Summarizer as a practical decision aid, not just a raw number or decorative conversion. First, confirm that the sample input represents the same kind of text you plan to publish, submit, paste, or share. Then compare the main output with the formula and notes above it. If a result looks surprising, change one input at a time and watch how the output changes. This makes the tool useful for planning, editing, and quality checks because you can see which setting actually moved the result.
Recommended workflow: Draft normally, paste the finished text into the tool, and make a first pass using the default settings. After that, adjust the options to match the real destination: a social platform limit, a document format, an audience reading speed, a Unicode style, a rewrite tone, or a summary length. Copy the output only after you have checked spelling, names, numbers, and context. For client work, classroom work, and publishing workflows, keep the original text nearby so you can compare the generated output before using it.
Quality checks: Review any transformed text in the exact app or editor where it will be used. Unicode effects, line breaks, sentence splitting, and platform limits can behave differently across devices and fonts. If the output will be read by customers, students, search visitors, or screen-reader users, prefer clarity over decoration. If the output is a calculation, treat it as an estimate and leave a small buffer. If the output is a rewrite or summary, verify that the meaning, facts, and tone still match your intent.
Validation tip: For repeatable work, save the input settings in your brief or checklist along with the copied result. A small note such as "12 pt, double spaced, normal margins" or "average reading speed, conversational speaking rate" prevents confusion later. For text generators, paste the output into a plain-text field first to confirm that it remains selectable, searchable, and visually acceptable. For summarizing and paraphrasing, compare at least one sentence against the source before sharing it with someone else. This extra review takes less than a minute and prevents most formatting, accuracy, context, and handoff mistakes in real publishing workflows and team reviews.
Privacy note: The working area is intentionally local. The JavaScript reads the fields already on this page, calculates or transforms the text in your browser, and writes the result back into the visible result box. That local workflow is why the page can be useful for drafts that are not ready for external services. The ad, analytics, and notification scripts are part of the shared site template, but the tool-specific text processing does not call a text API, upload your draft, or store the result.
Use Cases
- Article previews: Create a quick extractive summary before deciding whether to read a long article in full.
- Meeting notes: Condense long notes into the most keyword-rich sentences while keeping source wording visible.
- Research scanning: Identify important sentences in reports, essays, and documentation without uploading the text.
- Content editing: Compare the summary with the original to see whether the introduction and conclusion carry the main message.
- Study support: Turn dense paragraphs into a shorter review version while still checking highlighted source sentences.
Assumptions and Limitations
- This is extractive summarization, so it selects existing sentences rather than writing new abstractive sentences.
- TF-IDF favors distinctive repeated terms. A sentence can score highly because of keywords even if a human would choose a different sentence.
- Very short text with only one or two sentences cannot be meaningfully summarized by percentage.
- The sentence splitter is rule-based and may misread abbreviations, initials, or unusual punctuation.
Frequently Asked Questions
How to summarize a long text online
Paste your text — an article, a report, a chapter, anything — and pick how short you want the summary (usually as a percentage of the original length, or a target sentence count). The tool extracts the most important sentences and returns them as your summary. It uses extractive summarisation, meaning it picks real sentences from your text rather than rewriting them. Read the output, edit if needed, and copy. Quicker than skimming a 3000-word article when you need the key points.
How to make an article summary online
Paste the full article text into the summariser and choose your target length — short, medium, or long, or a specific number of sentences. The tool ranks every sentence by importance based on word frequency and position, then returns the top picks in their original order. Read the result against your knowledge of the article — extractive summaries occasionally pick odd sentences. Edit lightly if the flow is choppy. Useful for newsletters, social posts, and quick notes.
How to summarize text into bullet points
Run the summariser to get the key sentences first. Then format the output as bullets — most text editors let you select the lines and apply bullet formatting in one click. Or paste the summary into a Markdown editor and add - or * at the start of each line. The summariser doesn't natively output bullets in most modes because it produces full sentences, but converting the result to a bullet list is a five-second job afterward.
How to shorten a paragraph without changing meaning
Paste the paragraph into the summariser and pick a short target length — say, 30 to 50% of the original. The tool keeps the most informative sentences and drops the supporting or repetitive ones. Read the shortened version against the original to make sure no key idea has been cut. If something important was dropped, switch to a slightly longer summary length or paste the missing sentence back in manually. The output is a starting point you can polish.
How to get key sentences from an article
That's exactly what the extractive summariser does. Paste the article and the tool ranks every sentence by importance, then returns the highest-ranked ones as your "key sentences" output. You can adjust how many sentences you want — from a tight 3-sentence overview to a longer 10-sentence digest. Useful for quote pulling, social media post drafting, or building an executive summary from a longer report. The output uses the article's actual wording, not a rewrite.
How to summarize notes quickly online
Paste your notes into the summariser, pick a short target length, and the tool extracts the most important lines. Works best on notes that are written as full sentences. Bullet-point notes can come back oddly because the tool's algorithm assumes prose. If your notes are messy, paste them in anyway and treat the output as a rough first pass — copy what's useful, edit what isn't, and use it as the skeleton for a cleaner version.
How to make a summary without rewriting
Extractive summarisation is exactly that. The tool pulls actual sentences from your text and uses them word-for-word in the summary. No paraphrasing, no AI-generated rewrites, no risk of the summariser misrepresenting what the author actually said. Useful for academic work where direct quoting matters, for legal text where rewording could change meaning, and for content where you want the original voice preserved. Paste your text, set the length, copy the output.
Sources and References
- Wikipedia - TF-IDF - Background on term frequency and inverse document frequency scoring.
- Wikipedia - Automatic summarization - Overview of extractive and abstractive summarization methods.
- MDN - Regular expressions - Reference for token matching, sentence splitting, and local text parsing.
- Nielsen Norman Group - How Little Do Users Read? - Research on web reading patterns and scanning behavior.
Related Calculators
What this tool does
Text Summarizer turns the visible inputs on the page into a specific result and keeps the calculation context close to the form. The added notes identify what the output means, which assumptions matter, and when the result should be checked against source data or official guidance.
How to use this tool
- Enter the values requested by the form, keeping units, formats, and date fields consistent.
- Run the calculation or conversion and review each output label before using the result elsewhere.
- Compare important results with the page notes, examples, or official references when accuracy affects money, safety, configuration, or reporting.