humanflow

Free writing tools

19 small utilities that run entirely in your browser. No account, no limits, no upload — your text never leaves the tab.

That claim is worth being able to check rather than believe: what happens to your text sets out where it goes on each part of this site, including the parts that do reach a server. If you want to run any of this from your own code instead, the API and the MCP connector are both in private beta, and how to get access says what that currently means.

Text similarity checker

Measures how much two documents share, using the same 8-gram method this site runs on its own pages. Not a plagiarism checker.

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Lexical diversity calculator

Measures vocabulary variety with MATTR, which holds steady as your text grows — and shows why the usual type-token ratio does not.

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Reference checker

Cross-checks every citation against your reference list — missing entries, uncited sources, mismatched years. It cannot tell you a source is real.

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Nominalization finder

Finds verbs buried inside nouns — “made a decision” for “decided” — and names the verb that would replace the phrase.

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Quote checker

Checks every quotation in your writing against the source you paste, and shows what the source actually says where they differ.

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AI disclosure generator

Turns what you actually did into a plain-language disclosure statement you can adapt to your institution's wording.

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Sentence opener checker

Shows how every sentence begins and which openers repeat — the monotony sentence length alone will not reveal.

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Invisible character detector

Finds zero-width spaces, byte-order marks and look-alike letters hiding in pasted text — and strips them.

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Word & character counter

Words, characters, sentences, paragraphs — plus reading and speaking time, live as you type.

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Case converter

Switch between UPPERCASE, lowercase, Title Case and Sentence case, then copy the result.

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Text cleaner

Remove extra spaces and stray line breaks, straighten smart quotes, strip leftover Markdown.

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Sentence rhythm analyzer

Every sentence as a bar. Flat rhythm is what detectors flag — see yours at a glance.

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Text diff checker

Compare two versions word by word — additions in green, removals in red.

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Word frequency counter

Your most repeated words with counts and density — catch the crutch words.

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Character counter with platform limits

Live character count checked against X, Instagram, meta descriptions, app store listings and more.

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AI word finder

Highlights the words and phrases that make writing read as machine-generated, with counts for each.

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Essay structure checker

Paragraphing, signposting, citations and padding — the structural things the other tools don't look at.

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Readability checker

Flesch Reading Ease, Flesch–Kincaid grade and Gunning Fog — with an honest note on what they can't tell you.

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Prompt library

Eighteen prompts for getting first drafts that sound less machine-made, grouped by what you are writing.

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Need more than a utility?

HumanFlow rewrites AI drafts to read naturally and scores them for AI, with the signals behind the number — free up to 1,500 words per scan.

Try the humanizer free