Cheapest AI Writing Tool in 2025 – For just $1, Write 1 Million Words

There are countless AI writing tools on the market today, and while they promise impressive results, they often come with hefty price tags and monthly recurring fees. Writers, marketers, and content creators find themselves in search of a more budget-friendly alternative—something that doesn’t demand a subscription or hidden costs. That’s where OpenAI’s ChatGPT Completion API steps in.

With a pay-as-you-go model, ChatGPT allows you to generate content affordably, costing you just about $1 for around 1 million words (based on token usage). A token is approximately 3/4th of a word, and OpenAI’s GPT-4o mini model which is its most cost-efficient small model that’s smarter and cheaper than GPT-3.5 Turbo just costs $0.600 / 1M output tokens (roughly 750000 words), hence 1 million words for about $1.

Why Use ChatGPT Completion API as Your AI Writing Tool in 2025?

Cost-Effective: You pay only for the tokens you use, making it one of the cheapest AI writing tools on the market. There is no need to have a subscription, hence no recurring payments.

Easy to Implement: Integration is straightforward and can be done using almost any programming language or even cURL right from your terminal.

Scalable: Whether you need short social media posts or long-form articles, you can adjust the parameters to generate precisely the content you need.

Flexible: Customize the AI’s writing style and length by tweaking settings like temperature, max_tokens, and more to suit different projects.

More Than Just Writing: This API can be used no only to just write text, but also to do several other tasks from the given text, like Translation into different language, change the tone & writing style, grammar correction, summarize the long text, create list, convert the text to other formats like table, json, html or any other as per your requirements. This can be done by just supplying the right prompt along with the API call.

Cost Comparison with AI Writing Tools

Why I’m saying this is the cheapest AI writing tool ever, check out the below quick comparison of its pricing with some of the leading AI writing tools.

Tool Name	Pricing	OpenAI API Pricing
Writesonic	$20 per month for just 5 Articles	5 Articles of 1000 word each will cost you less than $0.10.
Writer.com	$18 for 15,000 words per month	For $18 you can write almost 18 million words 😮, that’s almost 1200 times more words 🤯!
Rytr	$29/m for Unlimited Articles but limited support for languages and tones	Officially Supports 60 languages and includes limited support for 38 extra languages

There are a few more in the league, However, these tools offer more features like integration with some apps & software, prebuilt prompts and settings for ease of use. But that all can be done just by adjusting the prompt and settings in API call.

How to Get Started?

1. Sign Up for OpenAI and Obtain an API Key

Head over to the OpenAI platform and create an account if you haven’t already.
After logging in, navigate to the API Keys section to generate your unique secret key.
Keep this key secure, as it authenticates your requests to the OpenAI servers.

2. Choose Your Implementation Method

cURL: Great for quick tests and demonstrations directly from the command line, or even from other programming languages.
Python: Ideal if you’re already familiar with Python and can use libraries like requests.
JavaScript: Common in web applications and easy to integrate using axios or fetch.
Other Languages: The pattern remains the same – make an HTTP POST request with the right headers and body parameters.

3. Sample Implementation Using cURL

Below is a simple cURL command that sends a request to OpenAI’s ChatGPT Completion API:

curl https://api.openai.com/v1/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_OPENAI_API_KEY" \
  -d '{
    "model": "gpt-4o-mini",
    "prompt": "Why AI Chatbots use tokens instead of words?",
    "max_tokens": 100,
    "temperature": 0.7
  }'

Customize Parameters for Your Needs

model: Choose the OpenAI model that suits your task best (e.g., gpt-4o-mini or gpt-4o or expensive o1 or o1-mini). You can check out all the models, their pricing on OpenAI API Pricing page.

prompt: Provide the text or instructions you want the AI to act upon. Prompt is basically counted as input token, and there are charges for the input token as well but just 1/4th of cost of output tokens.

max_tokens: Set an upper limit on how many tokens you want the AI to generate, remember a token is about 3/4th of a word, so if you choose 100 tokens, it may return about 75 words in response. This is however not needed in many cases.

temperature: Adjust the creativity or randomness of the output. A higher value (e.g., 0.9) produces more creative responses, while a lower value (e.g., 0.3) yields more focused results.

What If I don’t Know Programming?

If you don’t know how to program, getting started with OpenAI’s ChatGPT Completion API might sound intimidating at first—but it doesn’t have to be. One of the easiest ways to try it out is through a free tool like Postman (which lets you make API requests through a user-friendly interface).

After signing up for an OpenAI account to get your API key, simply open Postman, create a new request, and set the method to POST. Then, paste the OpenAI API endpoint (e.g., https://api.openai.com/v1/completions) into the address bar. In the headers section, add Content-Type: application/json and Authorization: Bearer YOUR_OPENAI_API_KEY. Finally, switch to the “Body” tab, select “raw,” choose JSON as the format, and type in the required fields, like which model you want to use, the prompt, and any additional settings (max_tokens, temperature, etc.).

Another no-coding approach is to use cURL from your computer’s command line, which might be more approachable than you think.

Get it done via a Freelancer

But still, Postman and cURL through command line interface are just for testing purposes, you might want to use this API embedded within your software, CMS or website (that’s the very purpose of using APIs). Here a programmer can help you, you can find tons of freelance programmers for this task on fiverr.com or upwork.com who can implement this within your choice of software / CMS.

It may cost you some dollars but that will be a one time cost, you will definitely end up saving much more in the long run.

I have basic understanding of programming

If you have only a basic understanding of programming concepts, ChatGPT itself can act as your personal tutor. You can ask ChatGPT how to integrate the Completion API in whatever language you’re comfortable with, be it Python, JavaScript, or even a simple cURL command.

For example, you could say,

“I’m new to PHP and cURL, and I want to use the OpenAI Completion API in my “WordPress” website. Can you write me the code and explain each step?”

ChatGPT will not only provide the code snippet but will also walk you through what each piece of the code does, line by line. By following these guided explanations, you’ll gradually be able to implement the API in your platform.

Furthermore, ChatGPT can also help you troubleshoot any errors you encounter. If something isn’t working as expected, copy the error message into ChatGPT and ask for guidance, often, it will point you to the likely cause of the issue and suggest changes or improvements.