Text Summarizer Dev tools
Automatically summarize long texts and extract key points using advanced algorithms
Text Summarizer
Paste a long article, report or transcript and get the sentences that carry the most information. The summary is built from the source text itself — nothing is paraphrased or invented — and every kept sentence stays highlighted in the original, so you can see exactly what was chosen and what was dropped. Runs entirely in your browser; your text is never uploaded.
Key terms
How This Summarizer Works
This is an extractive summarizer: it selects the most information-dense sentences from your text and returns them in their original order. It does not rewrite, paraphrase or generate new wording, which means the summary cannot introduce a claim your source never made — a failure mode that abstractive (AI-generated) summaries are prone to. Every sentence in the output appears verbatim in the input, and the tool shows you which ones by highlighting them in the source panel.
How Sentences Are Scored
| Signal | What it measures | Why it matters |
|---|---|---|
| Term frequency | How often a sentence's content words appear across the whole text, normalised per word | Sentences built from the document's recurring vocabulary are usually on-topic |
| Position | Distance from the beginning and the end | Opening sentences state the subject; closing ones often carry the conclusion |
| Length | Word count against a sweet spot | Fragments and headings carry little; 40+ word sentences dilute the summary |
| Numeric content | Presence of figures, dates and percentages | Concrete data is usually the part a reader wants kept |
Stop words — the, and, is in English, ve, bir, için in Turkish — are excluded from scoring so that common grammar does not drown out subject matter. The language is detected automatically, or you can set it manually.
Choosing a Length
The ratio slider controls what share of the original sentences survive, from 10% to 70%. The three presets are starting points: Short (15%) gives a headline-level gist, Medium (35%) is the usual choice for articles and reports, and Long (55%) works when you need to keep the supporting detail. Because the compression figure updates as you drag, you can dial in the exact trade-off between brevity and completeness rather than guessing.
Frequently Asked Questions
Is my text uploaded anywhere?
No. The summarizer runs as JavaScript in your browser — there is no server round-trip, so nothing is transmitted, logged or stored. You can verify this by opening DevTools → Network while typing, or by disconnecting from the internet after the page loads; the tool keeps working.
Does it use AI?
No language model is involved. It is a deterministic scoring algorithm: the same text and the same ratio always produce the same summary. That is a deliberate trade-off — the output is less fluent than an AI paraphrase, but it cannot hallucinate, drift off topic, or quietly change what your source said.
Why are some sentences greyed out?
The source panel shows the whole text with the selected sentences highlighted and the rest dimmed. That is the point of the layout: you can check at a glance whether the algorithm kept the parts you consider important, and drag the ratio slider until it does.
Does it work with Turkish?
Yes, with a dedicated Turkish stop-word list and Unicode-correct word handling. This matters more than it sounds: a common shortcut in PHP and older tooling is str_word_count(), which is ASCII-only and silently splits words containing ğ, ı, ş, ç, ö or ü — wrecking both the scoring and the keyword list. This tool tokenises on Unicode letter classes instead, so Turkish text is measured correctly.
What text length works best?
Anything from a few paragraphs upward. The algorithm needs at least three sentences to have something to choose between, and it gets more useful the longer the source is — a 3,000-word report compressed to 20% is where extractive summarising earns its keep. Very long documents are handled instantly; a 5,000-word text summarises in a few milliseconds.
Can I use this programmatically?
Yes — there is a REST endpoint at /api/v1/dev/text-summarizer for API-key clients, which returns the summary, statistics and keywords as JSON. The page you are on is the browser-side version and does not require an account.