You want a free AI writing plugin for WordPress that generates real blog posts without a monthly subscription. Six options advertise a free plan. Two of those free plans are genuinely usable for ongoing content. Two are free in name only, gated by word counts too small for a single post. Two are free because you bring your own API key, which means the plugin costs nothing but the AI usage does not. This comparison breaks down exactly what free means for each option, verified against each plugin’s official pricing page and WordPress.org listing as of August 2026.
If you are also comparing paid tiers and want the full cost math, our AI content writer pricing breakdown computes the real per-post cost across five tools. This page focuses exclusively on what you get for zero dollars.
What Free Actually Means Here
Free in the AI writing plugin world means three different things, and conflating them is how you end up surprised by a bill. Here is what each model actually means for your wallet.
Word-Credit Free Tiers: No API Key
GetGenie and Bertha AI give you a monthly word or credit allowance with no API key. The plugin handles the AI model behind the scenes. You generate content until you hit the limit, then you wait for the next month or upgrade. The plugin is free, the usage is free, and the limit is the catch. GetGenie gives you 2,500 words per month. Bertha gives you 500.
BYOK Free Tiers: Free Plugin, Paid Usage
AI Power (now rebranded as AI Puffer), AI Engine, and ClearPost’s free tier let you use the plugin at no cost, but every generation call routes through your own API key at OpenAI, Anthropic, or Google. You pay the AI provider directly for token consumption. The plugin adds no markup, but “free” means free software, not free usage. At GPT-4o Mini rates, a 2,000-word article costs roughly $0.001 to $0.003 in API fees. At GPT-4o rates, the same article costs $0.02 to $0.05. That is cheap, but it is not zero.
Free Trial Tiers: Time-Limited
ClearPost’s premium tier offers a 7-day free trial with no credit card required. You get the full SEO Agent, keyword research, content calendar, and autopilot publishing for 7 days, then it reverts to the free BYOK tier unless you upgrade. This is a trial, not a permanent free plan. The free tier itself (BYOK) is permanent and does not expire.
The ChatGPT Option: Free but Manual
ChatGPT’s free tier gives you unlimited everyday text chats with rate limits on premium features like image generation and file uploads, according to OpenAI’s help center as of August 2026. You can generate full blog posts in the ChatGPT interface, then copy-paste them into WordPress. The cost is zero dollars and 30 to 45 minutes of manual formatting per post: fixing heading hierarchy, adding internal links, writing meta descriptions, finding images, and clicking Publish. For a deeper look at why that manual labor dominates the real cost, see our guide to WordPress plugins that write blog posts.
Free Tier Limits, Side by Side
Here is what each free tier actually gives you, verified on each plugin’s official pricing page or WordPress.org listing. The “API Key Required” column is the one most people miss: it determines whether free means free usage or free software with paid usage behind it.
| Plugin | Free Monthly Limit | API Key Required | What Is Gated | WordPress Native |
|---|---|---|---|---|
| GetGenie | 2,500 AI words, 5 SERP analyses, 10 keyword analyses | No | Word count, SERP and keyword credits | Yes (plugin) |
| AI Power (AI Puffer) | Unlimited (BYOK) | Yes | Pro features: automations, RSS, integrations | Yes (plugin) |
| Bertha AI | 500 words, 5 images | No | Almost everything; WordPress plugin deprecated | No (Chrome extension only) |
| AI Engine | Unlimited (BYOK) | Yes | Pro features: AI Forms, embeddings, function calling, usage tracking | Yes (plugin) |
| ClearPost (free) | Unlimited (BYOK) | Yes | Premium: SEO Agent, calendar, autopilot, style matching | Yes (plugin) |
| ChatGPT Free | Unlimited text (rate-limited) | N/A (web interface) | No WordPress integration; manual copy-paste | No |
Plugins That Need Your Own API Key
Three of the six options in this comparison use a bring-your-own-key model. The plugin is free, but you pay OpenAI, Anthropic, or Google directly for the tokens you consume. Here is what each one gives you in the free tier and what the real API cost looks like.
AI Power (AI Puffer): Broadest Free Feature Set
AI Power, now listed on the WordPress.org directory as AI Puffer (with the note “formerly AI Power”), is the same plugin under a new name. The free version includes a chatbot builder, content writer, image generator, and AI forms. The plugin connects to OpenAI, Google Gemini, Microsoft Azure, OpenRouter, DeepSeek, xAI, and Anthropic through your own API key. There is no word limit or credit cap from the plugin itself. You pay the provider directly for every token.
The Pro plan at $9.99 per month adds advanced automations, voice agents, RSS feed content generation, WooCommerce product updates, Slack and HubSpot integrations, and security controls. For a full breakdown of where AI Power wins and where it creates friction, see our AI Power alternative comparison.
Where AI Power’s free tier is strong: breadth. You get a chatbot, content generator, image generator, and forms at no cost. Where it falls short: no keyword research, no SERP competitor analysis, no content calendar, no approval queue. Every post requires you to drive the interaction manually. The content writer works, but it does not ground drafts in what is actually ranking.
AI Engine: Developer-First, BYOK
AI Engine by Meow Apps has 100,000-plus active installs and takes a similar BYOK approach to AI Power, but goes deeper on developer tooling. The free version includes chatbots, an AI Copilot in the WordPress editor, a full-screen AI Workspace, content generation, image generation, AI training and finetuning, and a WordPress MCP server. The plugin was last updated with support for Claude Sonnet 4 and Opus 4 and Google Gemini models, according to the Meow Apps GitHub repository.
The Pro version starts at $79 per year for one site, $99 per year for five sites, and $179 per year for twenty sites, according to the official Meow Apps pricing page. Pro adds AI Forms, embeddings and vector databases, function calling to WordPress and WooCommerce, usage tracking with cost controls, an MCP server with advanced tools, and realtime audio chatbots.
Where AI Engine’s free tier is strong: developer depth. The MCP server, function calling, and REST endpoints give developers a serious framework for building AI-driven features into WordPress. The Copilot and Workspace are polished. Where it falls short: no keyword research, no SERP analysis, no content calendar, no autopilot publishing pipeline, no internal linking automation. If you want blog posts that rank, AI Engine gives you the generation layer but not the SEO pipeline.
ClearPost: Free Forever with BYOK, Premium Trial for the Full Pipeline
ClearPost’s free tier is permanently free, not a time-limited trial. According to the WordPress.org plugin listing, the free version includes one-click blog post generation using OpenAI, Anthropic, or Google Gemini with your own API key, AI-powered editing through a built-in chat interface, native Gutenberg block generation (no copy-paste), prompt history, 150-plus language support, and SEO plugin integration that auto-fills meta description, focus keyphrase, excerpt, and primary category for Yoast SEO, Rank Math, and AIOSEO.
Posts generate in draft mode. You approve every post before it goes live. That approval gate is the core design principle, not an afterthought. The free tier also includes a built-in MCP server for agentic SEO workflows.
The premium tier at $99 per month adds the autonomous SEO Agent, which researches keywords from your site’s data, builds a 30-day content calendar, generates posts that match your site’s established writing style, and publishes on autopilot. Premium also includes ClearPost’s own AI infrastructure, so no API key is needed. The 7-day free trial requires no credit card. For the full pricing breakdown including the Business tier at $199 per month, see the ClearPost pricing page.
We are going to be honest about the limitation here. The free tier gives you the generation and editing pipeline, but not the SEO research, content calendar, or autopilot scheduling. If you want the full pipeline with keyword research and automated publishing, that is the premium tier. The free tier is for users who already know what they want to write about and just need the generation and formatting handled inside WordPress.
The Real Cost of BYOK at Different Model Tiers
Here is what you actually pay per article when you bring your own API key, at current published OpenAI API rates. These are the rates the AI provider charges you, not what any plugin charges. The plugin takes no cut.
| Model | Input Rate (per 1M tokens) | Output Rate (per 1M tokens) | Est. Cost per 2,000-word Article |
|---|---|---|---|
| GPT-4o Mini | $0.15 | $0.60 | $0.001 to $0.003 |
| GPT-4o | $2.50 | $10.00 | $0.02 to $0.05 |
| Claude 4.5 Sonnet (Anthropic) | $3.00 | $15.00 | $0.03 to $0.08 |
At GPT-4o Mini rates, 30 articles per month costs roughly $0.03 to $0.09 in API fees. At GPT-4o rates, the same 30 articles costs $0.60 to $1.50. That is the real cost of a “free” BYOK plugin. It is dramatically cheaper than any SaaS subscription, but it is not zero, and it scales with your volume.
Where Free Is Too Limited to Be Useful
Not every free tier in this comparison is worth your time. Two of the six are honest about being trial-sized, and one has a structural problem that goes beyond the word count. Here is where free breaks down.
Bertha AI: 500 Words Is Not a Blog Post
Bertha AI’s free tier gives you 500 words per month and 5 image generations. A typical SEO blog post runs 1,200 to 2,000 words. The free tier covers roughly one-quarter of a single post. There is no keyword research, no SERP analysis, and no scheduling.
The bigger problem: the WordPress plugin is deprecated. Bertha’s own site states that the plugin no longer works with the latest version of WordPress and directs users to the Chrome extension instead. The extension works inside your browser while viewing the WordPress editor, but the native plugin integration that made Bertha convenient is gone. The plugin was closed on the WordPress.org repository following a compliance review, and Bertha’s team stated the remediation work would take over 50 hours for a product that had reached a natural stopping point.
Bertha’s paid plan starts at $160 per year. At that price point, GetGenie’s paid Starter plan at $9.99 per month gives you 20,000 words and SERP analysis. Bertha is not competitive on free, and it is not competitive on paid. For a deeper comparison, see our WordPress SEO plugin comparison.
GetGenie: Usable for Testing, Not for Production
GetGenie’s free plan gives you 2,500 AI words per month, 5 SERP competitor analyses, and 10 keyword analyses. That is enough for one blog post of moderate length, plus a handful of keyword research sessions. The SERP competitor analysis is genuinely useful: it pulls top-ranking pages for your target keyword, analyzes their content structure, word count, and heading hierarchy, then generates a content brief grounded in what is actually ranking.
The problem is volume. One post per month is not a content strategy. If you publish weekly, you exhaust the free tier in the first week. GetGenie does not allow you to bring your own API key, so you cannot bypass the word limit by paying OpenAI directly. You upgrade to a paid plan or you wait.
Where GetGenie’s free tier is genuinely valuable: evaluation. If you want to test whether AI-generated content works for your niche before paying, the free plan lets you generate one real post with real SERP data behind it. That is a better test than generating a post in ChatGPT with no keyword research. But for ongoing production, 2,500 words per month is a sample, not a pipeline.
ChatGPT Free: Unlimited Text, Unlimited Manual Labor
ChatGPT’s free tier is technically the most generous on raw text generation. You get unlimited everyday text chats, subject to abuse-prevention safeguards, with access to a current GPT model. You can prompt it to write a full 2,000-word blog post with proper heading structure, and it will.
The cost is not in the generation. It is in the publishing. Every post requires manual transfer: copy the text from ChatGPT, paste it into WordPress, fix the heading hierarchy that broke during the paste, manually add internal links to existing posts, write a meta description, set the title tag, assign categories and tags, find and upload a featured image, write alt text, and click Publish. That process takes 30 to 45 minutes per post. At 8 posts per month, that is 4 to 6 hours of formatting labor. For more on why that labor dominates the real cost of content production, see our analysis of how many blog posts you need before traffic shows up.
Which Free Option Fits Which Situation
Stop asking which free AI writing plugin is best and start asking which one solves your actual bottleneck. The answer depends on what you are trying to do with zero budget.
If You Want to Test AI Content Before Paying
GetGenie’s free tier is the best test drive. You get 2,500 words with real SERP competitor analysis and keyword research, which is more than any other free option provides in terms of SEO grounding. One post per month is enough to evaluate whether AI-generated content works for your niche, your tone, and your audience. No API key, no billing setup, no configuration. Install the plugin, claim your free license, and write one post.
If You Want Unlimited Generation at Minimal Cost
AI Power (AI Puffer) or AI Engine with your own API key. Both give you unlimited generation with no word cap from the plugin. You pay OpenAI or Anthropic directly, which means your cost is roughly $0.01 to $0.05 per article depending on the model. AI Power has the broader feature set (chatbot, images, forms). AI Engine has the deeper developer tooling (MCP server, function calling, REST endpoints). Neither includes keyword research or a publishing pipeline. You generate content manually, post by post.
If You Want the Full SEO Pipeline Free
ClearPost’s free tier with BYOK is the closest to a complete pipeline at zero software cost. You get one-click generation, native Gutenberg blocks, AI-powered editing, SEO plugin integration (Yoast, Rank Math, AIOSEO), and an approval gate where every post generates as a draft. You bring your own API key for the generation layer. The gaps versus premium: no autonomous keyword research, no content calendar, no autopilot scheduling, no style matching. If you already know your keywords and just need the generation and formatting handled inside WordPress, the free tier covers that.
If You Want Zero Setup and Zero Cost
ChatGPT free plus manual publishing. No plugin to install, no API key to configure, no settings to manage. You paste your prompt into ChatGPT, get a draft, and spend 30 to 45 minutes formatting it for WordPress. The cost is zero dollars and your time. This works for one or two posts per month. At 8 or more posts per month, the manual labor becomes the bottleneck, and a plugin that handles formatting and publishing starts paying for itself in saved hours.
If You Want to Evaluate the Full Pipeline Before Committing
ClearPost’s 7-day premium trial gives you the complete workflow: keyword research from your site’s data, a 30-day content calendar, autopilot publishing, style matching, and the SEO Agent. No credit card required. You see what 30 SEO-optimized posts per month looks like before paying anything. After 7 days, the premium features revert and you keep the free BYOK tier. If your bottleneck is the publishing workflow rather than generation cost, that trial is where you find out.
If you want the full pipeline without the manual labor, that is what we built at ClearPost. AI does the keyword research, drafting, on-page SEO, internal linking, and publishing to WordPress. You approve every post before it goes live. No copy-pasting from a separate tool, no 30-minute formatting ritual per article, no manual meta tag writing. The approval gate is built in, not bolted on. See what 30 SEO-optimized posts a month looks like compared to the 4 you are getting now. Try ClearPost free for 7 days. AI does the heavy lifting, you approve every post before it goes live. No long onboarding, no agency overhead, cancel anytime.
Frequently Asked Questions
Which free AI writing plugin has the best free tier for WordPress?
It depends on what you need. GetGenie’s free plan gives you 2,500 words per month with SERP analysis and keyword research, which is the most SEO-grounded free option but limited to roughly one post per month. ClearPost’s free tier gives you unlimited generation with your own API key, native Gutenberg blocks, SEO plugin integration, and an approval gate, which is the most complete pipeline but requires paying OpenAI or Anthropic directly for token usage. AI Power (AI Puffer) offers the broadest feature set for free with BYOK, including chatbot, images, and forms.
Do free AI writing plugins require an API key?
Some do, some do not. GetGenie and Bertha AI do not require an API key because they handle the AI model behind the scenes with their own word-credit system. AI Power (AI Puffer), AI Engine, and ClearPost’s free tier all require you to bring your own API key from OpenAI, Anthropic, or Google. The plugin is free but you pay the AI provider directly for token usage, typically $0.001 to $0.05 per article depending on the model. ChatGPT’s free tier does not require an API key but has no WordPress integration.
Is Bertha AI’s free plan usable for WordPress?
No. Bertha AI’s free tier gives you 500 words per month, which is less than one-quarter of a single blog post. More importantly, the WordPress plugin has been deprecated and no longer works with the latest version of WordPress. Bertha now operates as a Chrome extension only. The free plan is too small for practical use, and the paid plan starting at $160 per year is not competitive with alternatives like GetGenie at $9.99 per month or ClearPost’s free BYOK tier.
Can I generate unlimited blog posts for free on WordPress?
Yes, but only with a bring-your-own-key plugin. AI Power (AI Puffer), AI Engine, and ClearPost’s free tier all allow unlimited generation with no word cap from the plugin. You pay the AI provider directly for token usage at roughly $0.001 to $0.05 per article depending on the model. GetGenie and Bertha AI cap your free generation at 2,500 and 500 words per month respectively, with no way to bypass the limit by bringing your own API key.
What is the difference between ClearPost free and premium?
ClearPost’s free tier is permanently free with your own API key and includes one-click generation, native Gutenberg blocks, AI-powered editing, prompt history, SEO plugin integration, and an approval gate. The premium tier at $99 per month adds the autonomous SEO Agent, keyword research from your site’s data, a 30-day content calendar, autopilot publishing, style matching, and ClearPost’s own AI infrastructure so no API key is needed. Premium includes a 7-day free trial with no credit card required.