Can free AI help with ENEM essays? Yes, but with important limitations
Studying for ENEM in 2026 means dealing with an offer of artificial intelligence tools that didn’t exist just a few years ago. Today you can submit a text to an AI, receive a detailed analysis of competencies, identify where you lost points in argumentation, and even ask for suggestions of cultural references. All of this for free, without paying anything.
The problem is that not every AI serves this purpose, and using the wrong tool can give you false confidence. An AI that praises everything you write is worse than no AI. That’s why this guide compares the most accessible and available options in Brazil in 2026, explains what each one does well and what you shouldn’t expect from them.
The short answer: ChatGPT, Gemini, and Copilot are the best free choices for practicing ENEM essays, each with a different profile. See which fits your study style.
What an AI can (and cannot) do for your essay
Before testing any tool, understand what you’re getting. The AIs available today are language models (systems trained on enormous volumes of text to predict and generate coherent responses). They don’t have access to Inep’s official grading rubric, they don’t grade your essay with the same precision as a specialist teacher, and they don’t guarantee a perfect score of 1000.
What they do well is structural analysis. You paste your text, ask for an evaluation across the five ENEM competencies (mastery of standard language, comprehension of the theme, organization of arguments, use of cohesion mechanisms, and intervention proposal) and receive a useful diagnosis. The AI identifies if your introductory paragraph didn’t delimit the theme, if connecting words were missing between ideas, or if your intervention proposal doesn’t answer the questions “who does what, how, with what purpose”.
Another real utility is expanding your repertoire. You can ask the AI to suggest data, philosophical, literary, or scientific references related to your essay’s theme. Always verify the facts cited before using them, because AIs still make factual errors, especially with dates and specific numbers.
Comparison of main free AIs for ENEM 2026 essays
| Tool | Company | Free access | Free plan limit | Works in Portuguese? | Best for |
|---|---|---|---|---|---|
| ChatGPT (GPT-4o) | OpenAI | Yes | Limited GPT-4o use; unlimited GPT-4o mini | Yes, very well | Detailed correction by competency |
| Gemini (1.5 Flash) | Yes | No stated limit for basic use | Yes, native | Google Docs integration | |
| Microsoft Copilot | Microsoft | Yes | No limit for basic browser use | Yes | Those already using Edge or Bing |
| Claude (Haiku) | Anthropic | Yes | Daily message limit | Yes | Long texts and cohesion analysis |
| Perplexity AI | Perplexity | Yes | Limit on in-depth searches | Yes | Repertoire research with sources |
ChatGPT: the most versatile for essay practice
OpenAI’s ChatGPT remains the market reference in 2026. In the free plan, you access the GPT-4o mini model without restrictions on quantity and GPT-4o with limited use per time window. For essay study purposes, GPT-4o mini already delivers competent analysis in most cases.
The major advantage of ChatGPT for ENEM is the flexibility of prompts (instructions you give the AI). If you type “correct my text following the five ENEM competencies and give an estimated score of 0 to 200 for each one”, the model understands the request and structures the response in an organized way. You can ask for rewrites of specific paragraphs, suggestions for connectives, criticism of your intervention proposal, or even simulation of other themes.
The point to watch is that ChatGPT sometimes tends to soften criticism when you insist your text is good. Be direct in your prompt: ask it to point out at least three serious problems, even if the text seems adequate. This better calibrates the response.
Gemini: the natural choice for those living in the Google ecosystem
If you use Google Docs to write your essays, Google’s Gemini is the most practical choice. It’s directly integrated into Docs and Gmail, which means you can ask for text analysis without needing to copy and paste anything.
The Gemini 1.5 Flash model is available for free and, according to Google, was optimized for text tasks with low latency (faster response). In Portuguese, performance is solid. Text cohesion analysis, which involves identifying whether paragraphs connect logically, is usually a strong point.
Gemini also has real-time internet access, which is useful when you ask for data for argumentation. If you want numbers on educational inequality in Brazil for an essay on that topic, Gemini can search for updated information, with the caveat that you should verify the data from reliable sources before using it in your essay.
Microsoft Copilot: solid option for those using Windows and Edge
Microsoft Copilot works directly in the Edge browser and is available without mandatory login for basic use. It runs on OpenAI models, so language performance is close to ChatGPT. The difference lies in the interface: Copilot has conversation modes like “Creative”, “Balanced”, and “Precise” that adjust the tone of responses.
For essay correction, the “Precise” mode works better. It tends to be more objective in criticism and less prone to unnecessary praise. Integration with Bing allows it to search data on the internet during the conversation, functioning similarly to Gemini in this regard.
If you have a Windows notebook and want a tool that works well without creating new accounts, Copilot is a good entry point. For those still researching which notebook to buy for studies, the guide on the best notebook up to 4 thousand reais in 2026 can help you make that decision before diving into studies.
Claude and Perplexity: options for specific uses
Claude from Anthropic stands out in analyzing long texts. If you’re practicing extended essays or want the AI to analyze multiple of your texts in sequence, Claude maintains conversation context better than some competitors. The free plan has a daily message limit, but for focused study use this is rarely a problem.
Perplexity AI is different from the others: it functions more like an advanced search engine than a corrector. If you need to build solid repertoire for a specific theme (public policies, environment, technology and society), Perplexity searches for information with references to original sources, making verification easier. It’s not the best tool for correcting your essay, but it’s excellent for the research phase before writing.
How to use AI to really train (not just feel good)
The most common mistake people make using AI to study essays is treating the tool as a validator, not as a critic. Here’s a sequence of use that works:
- Choose a real ENEM theme from recent years and write your essay without AI help, in exam time (30 minutes).
- Paste the text into the AI and ask for analysis across the five competencies, requesting an estimated score of 0 to 200 for each.
- Read the diagnosis and identify the competency with the poorest performance.
- Ask the AI to rewrite only the problematic section, explaining what changed and why.
- Rewrite the paragraph yourself, based on the explanation, without copying the AI’s text.
- Repeat the process with a new theme next week.
Step 5 is the most important. The AI can show the way, but rewriting yourself is what develops real skill. Copying text generated by AI doesn’t prepare you for exam day inside the testing room.
Frequently asked questions about AI for ENEM essays
Can AI replace an essay teacher?
No. AI is an efficient support tool for quick diagnosis and constant practice, but it doesn’t have the pedagogical sensitivity of an experienced teacher. For those without access to private lessons, it’s a real and valuable alternative. For those with access to both, the ideal is to combine them.
Is the score the AI gives close to the real ENEM score?
There’s no guarantee of this. AIs don’t have access to Inep’s official grading rubric and weren’t specifically calibrated for the exam. Estimated scores serve as relative reference (comparing your own texts over time), not as reliable prediction of your actual score.
Can I use AI to write the essay for me and just adjust it?
Technically yes, but it doesn’t work as preparation. Inside the testing room you’re alone, without any tools. If all your practice was based on AI-generated texts, you arrive on exam day without having developed the skills it evaluates.
Do I need to pay a subscription for good results?
Not necessarily. For the specific goal of practicing ENEM essays, the free plans of ChatGPT, Gemini, and Copilot deliver enough. Paid versions bring advantages like more conversation memory and more powerful models, but aren’t essential for this use.
The best use of free tools lies in consistency
None of these tools will give you a perfect 1000 score by themselves. What they do is accelerate the feedback cycle: instead of waiting days to receive a teacher’s correction, you get a diagnosis in seconds and can practice more times in the same week.
For most students, the practical recommendation is to start with ChatGPT with the free model and, if you already live in the Google ecosystem, try Gemini through Docs integration. The most important thing is to establish a weekly writing routine, use AI as honest criticism, and never skip the step of rewriting the text yourself.