The best way to not sound like AI is to write clearly, specifically, and with personality. These tools help you do exactly that.

We’ve divided this guide into two categories: clarity tools that help you write better, and AI detection tools that let you check your work before publishing.

Nobody Is Safe

Here’s the uncomfortable truth: even experienced writers fall into AI-sounding patterns. We’ve all used “delve” without thinking, started emails with “I hope this finds you well,” or leaned on passive voice when we’re tired. These tools aren’t just for catching AI-generated content. They’re for catching ourselves when we slip into robotic autopilot.

Want the full playbook? Check out our complete guide on how to humanize AI content, including the 34-rule prompt and words to avoid.

Part 1: Clarity & Readability Tools

These tools help you write cleaner, more direct prose. They catch the kind of bloated, passive, overly complex writing that AI often produces.

Hemingway Editor

Best for: English writers who want punchy, readable prose

Hemingway Editor is the gold standard for clarity. It highlights:

Hard-to-read sentences (yellow and red highlights)
Passive voice (a major AI tell)
Adverbs that weaken your writing
Complex phrases with simpler alternatives

Free tier: Full web app access Paid: Desktop app ($19.99 one-time)

Limitation: English only. Spanish writers need alternatives (see below).

Pro tip: Aim for Grade 9 or lower readability. Most viral content sits at Grade 6-8.

LanguageTool

Best for: Multilingual writers, especially Spanish

LanguageTool supports 30+ languages, including Spanish, French, German, Portuguese, and more. It’s the closest thing to Hemingway for non-English writers.

What it catches:

Grammar and spelling errors
Punctuation issues
Style suggestions (wordy phrases, overused words)
Context-aware corrections (there/their, a/an)

Free tier: Basic proofreading, unlimited use Premium: $12/month for advanced style rules

Spanish-specific features:

Detects tú/usted inconsistencies
Regional spelling variations (Latin America vs Spain)
Gender agreement errors

Browser extensions: Chrome, Firefox, Google Docs, Word

Grammarly

Best for: English writers who want real-time suggestions everywhere

Grammarly offers more than grammar checking. Its tone detector helps you understand how your writing comes across.

What it catches:

Grammar and spelling
Tone analysis (confident, friendly, formal, etc.)
Clarity suggestions
Engagement improvements

Free tier: Basic grammar and spelling Premium: $12/month for full features

AI-specific help: Grammarly now flags “AI-sounding” phrases and suggests more natural alternatives.

ProWritingAid

Best for: Long-form writers who want deep analysis

ProWritingAid offers 20+ writing reports including readability, sentence variety, and “sticky sentences” (sentences with too many glue words).

Standout features:

Sentence length variation graphs
Overused word reports
Clichés and redundancy detection
Writing style comparisons

Free tier: 500 words per check Premium: $20/month or $399 lifetime

QuillBot

Best for: Paraphrasing AI content to sound more natural

QuillBot is a paraphrasing tool that rewrites sentences while preserving meaning. It’s particularly useful for taking AI-generated drafts and making them sound more human.

What it offers:

Paraphraser: Rewrites text in different styles
Grammar Checker: Catches errors and awkward phrasing
Translator: Supports English-Spanish translation
AI Detector: Built-in detection tool

Free tier: 2 modes (Standard & Fluency), basic grammar check Premium: $50/year for 11+ paraphrasing modes (Formal, Custom, etc.)

Paraphrasing modes:

Standard: Replaces words with synonyms, rearranges word order
Fluency: Improves clarity and readability
Formal/Creative/etc.: Premium modes for specific tones

Spanish support: Available but limited. Not all paraphrasing modes work in Spanish, and quality can be inconsistent. For Spanish, combine with LanguageTool for best results.

Browser extensions: Chrome, Firefox, Google Docs, Word

Part 2: AI Detection Tools

Use these to check your content before publishing. Remember: the goal isn’t to “fool” detectors, it’s to ensure your writing genuinely sounds human.

GPTZero

Best for: Most reliable free option

GPTZero is consistently rated the most accurate AI detector. G2 ranked it #1 for reliability in 2025.

What it analyzes:

Perplexity: How surprising your word choices are
Burstiness: How much your sentence length varies
Probability scores: Likelihood each sentence is AI-generated

Free tier: 10,000 words/month (about 15,000 characters) Premium: From $12.99/month

Accuracy: 99% on diverse datasets. Works with ChatGPT, GPT-4, Claude, Gemini, and Llama content.

Highlight: Shows you exactly which sentences triggered detection, so you know what to rewrite.

Originality.ai

Best for: Professional content teams

Originality.ai combines AI detection with plagiarism checking. Designed for publishers and agencies.

What it offers:

AI detection (ChatGPT, GPT-4, Claude, etc.)
Plagiarism checking
Readability scores
Team collaboration features

Pricing: From $14.95/month (no free tier)

Accuracy: 76-94% depending on content type. Sometimes over-flags human writing.

Best for: When you need both AI detection and plagiarism checking in one tool.

Copyleaks

Best for: Enterprise and education

Copyleaks offers near-perfect AI detection with the lowest false positive rates in testing.

Standout features:

LMS integrations (Canvas, Blackboard, Moodle)
API access for developers
Multi-language support
Source code plagiarism detection

Pricing: Custom pricing, free trial available

Note: Particularly strong at not flagging legitimate human writing as AI.

Pangram Labs

Best for: Writers who want detailed analysis

Pangram claims an industry-leading false positive rate of 1 in 10,000.

What makes it different:

Sentence-by-sentence analysis
Vocabulary pattern detection
Writing style fingerprinting
Free tier available

Free tier: Limited checks Premium: Starting at $9.99/month

ZeroGPT

Best for: Quick, free checks

ZeroGPT is completely free and offers instant results.

Features:

No word limit
No registration required
Batch checking available
Chrome extension

Limitation: Less accurate than GPTZero or Originality on mixed content.

Best for: Quick sanity checks when you don’t need deep analysis.

Rankability

Best for: SEO writers

Rankability is completely free and specifically designed for content writers.

In 2026 testing, it was one of only three tools (alongside Copyleaks and Originality) that correctly flagged all AI content while treating human writing as human.

Features:

100% free
SEO-focused analysis
Content optimization suggestions
AI detection

Quick Comparison Table

Tool	Best For	Free Tier	Spanish Support	Accuracy
GPTZero	Overall detection	10K words/mo	Limited	99%
Originality.ai	Professional teams	No	Limited	76-94%
Copyleaks	Enterprise	Trial	Yes	95%+
Pangram	Detailed analysis	Limited	Limited	High
ZeroGPT	Quick checks	Unlimited	Limited	Moderate
Rankability	SEO content	Unlimited	Limited	High

Our Recommended Workflow

Write your draft (AI-assisted or not)
Run through Hemingway/LanguageTool to catch passive voice, complex sentences, and clarity issues
Apply the 34-rule checklist from our humanize AI content guide
Check with GPTZero (free tier works for most needs)
Rewrite flagged sentences focusing on specificity and voice
Read aloud as a final check. If it sounds robotic, rewrite it.

The Bottom Line

Tools help, but they don’t replace judgment. The best way to not sound like AI is to:

Write about specific experiences
Include opinions and uncertainty
Vary your sentence structure naturally
Use contractions and casual language where appropriate

These tools catch the mechanical issues. Your voice provides the human element no tool can replicate.

Get the Complete System

Tools are just part of the equation. Our complete guide includes the 34-rule prompt, words to avoid by category, platform-specific strategies, and an interactive quiz to test your skills.

Read: How to Make AI Content Sound Human →

Best Tools to Write Like a Human: Clarity Editors + AI Detectors (2026)