Short answer
These six tools cover different steps of a content workflow. Rytr is low-cost everyday drafting. Koala, SEOWriting.ai and Scalenut generate long-form SEO articles (Scalenut also tracks AI-search visibility). Originality.ai checks text for AI generation and plagiarism. WriteHuman rewrites AI drafts to read more naturally. Search engines reward helpful, accurate content however it is made, so every option here still needs a human edit.
All 6 at a glance
| Tool | Best for | Free plan | Entry paid plan | Link |
|---|---|---|---|---|
| freelancers and small businesses that need quick, affordable copy | Free: 10K characters/mo | Unlimited: $7.50/mo billed yearly | Try Rytr ↗Affiliate link | |
| publishers, editors and agencies vetting content | Basic: free, AI detection only, 3 scans/day, 2,000 words/scan | Pro: $12.95/mo billed annually · $14.95 monthly | Try Originality.ai ↗Affiliate link | |
| writers who want AI drafts to read more naturally | Free: 3 humanizer requests/mo, up to 250 words each | Basic: $20/mo billed monthly · $12/mo billed annually (80 requests/mo) | Try WriteHuman ↗Affiliate link | |
| bloggers and affiliate sites publishing content at volume | Free: 3 articles, up to 25,000 words, no payment details needed | Starter: $19/mo billed monthly · $14/mo billed yearly (up to 50 articles) | Try SEOWriting.ai ↗Affiliate link | |
| marketers and agencies running content-led SEO | 7-day free trial on Starter, Plus and Professional (no free forever plan listed) | Starter: $59/mo billed monthly · $24/mo billed annually on the listed 60%-off promo (track 10 prompts; 5–10 articles/mo) | Try Scalenut ↗Affiliate link | |
| site owners who want an AI agent to plan and write SEO articles | Free start: 5,000 words and 25 credits, no credit card required | Starter: $25/mo billed monthly (45,000 words, 500 credits per month) | Try Koala AI ↗Affiliate link |
Each tool’s section below shows the date its prices were checked on the vendor’s official pricing page. Scores are pending until we test. Want two side by side? Use the compare tool.
How to choose
Decide which step you need help with
Drafting short copy, producing long SEO articles, checking originality and editing tone are different jobs. Buying an article generator will not fix an editing bottleneck.
Price by output, not by plan name
Plans are sold by words, articles, credits or requests. Work out how many publishable pieces you need a month, then compare what each plan delivers at that volume.
Budget time for fact-checking
AI drafts can state wrong facts confidently. Plan an editor pass for every piece, especially prices, statistics and medical, legal or financial claims.
Treat AI detectors as a signal, not a verdict
Detectors, including the one built into WriteHuman, give probabilities and can be wrong both ways. Use them to flag text for review, not to accuse anyone.
1. Rytr
Rytr is an AI writing assistant that drafts blog posts, emails, ads, social posts and other copy from short prompts. You pick a use case and tone, and it can learn to write in your own voice. It works in many languages.
Best for: freelancers and small businesses that need quick, affordable copy.
| Free plan | Free: 10K characters/mo |
|---|---|
| Entry paid plan | Unlimited: $7.50/mo billed yearly |
| Next tier up | Premium: $24.16/mo billed yearly |
| Listed highlight | Unlimited generations on paid plans; 35+ languages on Premium |
Rytr pricing
Try Rytr ↗Affiliate linkRelated: AI Writing and SEO Content Stack
2. Originality.ai
Originality.ai checks whether text was written by AI tools such as ChatGPT, Gemini or Claude. It also offers plagiarism checking, fact checking and readability tools. Publishers and agencies use it to review content before it goes live.
Best for: publishers, editors and agencies vetting content.
| Free plan | Basic: free, AI detection only, 3 scans/day, 2,000 words/scan |
|---|---|
| Entry paid plan | Pro: $12.95/mo billed annually · $14.95 monthly |
| Next tier up | Enterprise: $136.58/mo billed annually |
| Listed highlight | 2,000 credits/mo on Pro (1 credit = 100 words) |
Originality.ai pricing
Try Originality.ai ↗Affiliate linkRelated: AI Writing and SEO Content Stack
3. WriteHuman
WriteHuman is an AI humanizer that rewrites AI-generated text so it reads more naturally. It includes its own AI detector so you can check text before and after. You paste text in, choose settings and get a rewritten version.
Best for: writers who want AI drafts to read more naturally.
| Free plan | Free: 3 humanizer requests/mo, up to 250 words each |
|---|---|
| Entry paid plan | Basic: $20/mo billed monthly · $12/mo billed annually (80 requests/mo) |
| Next tier up | Pro: $29/mo billed monthly · $19/mo billed annually (200 requests/mo) |
| Listed highlight | AI detector included; Ultra ($39/mo billed annually) has unlimited requests |
WriteHuman pricing
Try WriteHuman ↗Affiliate linkRelated: AI Writing and SEO Content Stack
4. SEOWriting.ai
SEOWriting.ai generates SEO-optimized blog posts and affiliate articles in one click, including structured outlines, images and product lists. It can create articles in bulk and publish them automatically to WordPress. It is aimed at site owners who need a lot of search-focused content.
Best for: bloggers and affiliate sites publishing content at volume.
| Free plan | Free: 3 articles, up to 25,000 words, no payment details needed |
|---|---|
| Entry paid plan | Starter: $19/mo billed monthly · $14/mo billed yearly (up to 50 articles) |
| Next tier up | Professional: $79/mo billed monthly · $59/mo billed yearly (up to 250 articles) |
| Listed highlight | Bulk generation, brand voices and internal linking on paid plans |
SEOWriting.ai pricing
Try SEOWriting.ai ↗Affiliate linkRelated: AI Writing and SEO Content Stack
5. Scalenut
Scalenut is an AI SEO platform for keyword research, content planning, writing and optimizing articles. It also tracks how visible your brand is in AI search answers and offers expert-led SEO services. It is meant to cover organic growth from research to published content.
Best for: marketers and agencies running content-led SEO.
| Free plan | 7-day free trial on Starter, Plus and Professional (no free forever plan listed) |
|---|---|
| Entry paid plan | Starter: $59/mo billed monthly · $24/mo billed annually on the listed 60%-off promo (track 10 prompts; 5–10 articles/mo) |
| Next tier up | Plus: $89/mo billed monthly · $36/mo billed annually on promo (track 25 prompts; 30–60 articles/mo) |
| Listed highlight | Professional: $199/mo billed monthly · $80/mo billed annually on promo (track 100 prompts; 75–150 articles/mo) |
Scalenut pricing
Try Scalenut ↗Affiliate linkRelated: AI Writing and SEO Content Stack
6. Koala AI
Koala AI is an AI SEO platform. An SEO agent reads your Google Search Console data to suggest what to publish, its KoalaWriter drafts articles in your voice, and you can publish to your CMS in one click. It also includes keyword, backlink and competitor research.
Best for: site owners who want an AI agent to plan and write SEO articles.
| Free plan | Free start: 5,000 words and 25 credits, no credit card required |
|---|---|
| Entry paid plan | Starter: $25/mo billed monthly (45,000 words, 500 credits per month) |
| Next tier up | Professional: $49/mo billed monthly (100,000 words, 1,000 credits per month) |
| Listed highlight | Boost: $99/mo (250,000 words); annual billing saves 20% |
Koala AI pricing
Try Koala AI ↗Affiliate linkRelated: AI Writing and SEO Content Stack
FAQ
What is the cheapest AI writing tool?
Rytr lists the lowest paid price here: Unlimited at $7.50/mo billed yearly, plus a free plan with 10K characters a month (checked Oct 15, 2026).
Which AI writing tools are built for SEO articles?
Koala, SEOWriting.ai and Scalenut focus on long-form SEO content. SEOWriting.ai lists a free tier of 3 articles; Koala lists a free start of 5,000 words; Scalenut lists a 7-day free trial.
Does WriteHuman make text undetectable?
We do not recommend relying on any tool for that. WriteHuman rewrites AI text to read more naturally and includes a detector, but no humanizer can guarantee how a given detector will score text, and passing a detector is not the same as being helpful or original. Disclose AI use where your school, client or platform requires it.
Do I need an AI detector like Originality.ai?
Publishers and agencies that accept outside writing use it to screen submissions. It lists a free Basic tier (AI detection only, 3 scans a day). Treat results as one input alongside an editor’s judgment.
Last updated Oct 15, 2026 by TrendingAI Editorial. We list facts from official vendor pages and will add hands-on scores as we test. See how we make money.