How to Detect AI-Written Cover Letters in 2025 (and Why It Matters)

CoverSentry's mission is to help detect AI language in cover letters. So, how do you know if something is AI-written?

How to detect AI in writing

We humans tend to write in a non-perfect way, which is exactly the juice that differentiates us from them. This means that we make mistakes, we don't always use the right word for each occasion, we aren't perfect. That is what it means to be human.

Often when I ask an AI to re-write an awkward phrase, it spits out a bunch of sentences no human would naturally write. The example below is a bit extreme, but describes the matter well enough:

See, the word choices are something that humans just don't tend to pick. Why? What makes us write in a more simple manner? Maybe we don't naturally use such sophisticated words, which leaves our neural pathways unused when it comes to those structures. Or maybe it's an assumption that they are just... too much. And they are.

So why does an AI make those choices? One answer is that they try to compress as much information to a single sentence as possible, which leads to over complicated word structures. There are ideas, but discussing the whys doesn't change the reality. AI text is detectable, and we as humans just feel that something is off.

That's the notch that CoverSentry is trying to touch: the feeling. If we as humans have a scent that this text is AI-written, something lights up in our minds. That's the type of text that our AI checking tool would alert us for.

Then again, even if the text actually is AI-written, but if it reads like a human, our tool would stay silent. We optimize our AI text scanning tool to be as human as possible. There are ways to make deeper analysis on the text, but that's a story for another time.

Is it ok to use an AI to write cover letters?

We specialize in the psychology of hiring. It's something that tickles my pickle, so to speak (ha, get an AI to naturally come up with that). Almost every person on the planet gets employed at some point in their lives, which means that this topic touches us all.

It is not a secret, that some people decide to have an AI write their cover letters. If that happens at a large scale (and it does), that makes the topic less of a niche and more like a mainstream phenomenon / problem, whichever side you are looking at this from.

It is known that 80% of hiring managers dislike AI-written cover letters [source]. However, a tired job seeker who has applied to hundreds of positions thanks AI for existing, and proudly writes most of their cover letters using the said AI. So, which is it?

I'm afraid there is no definitive answer. It depends.

At this point we know that every year millions of cover letters are generated by AI. Like discussed in the previous chapter, the language AI uses can be too robotic and fancy. What does that tell us?

Imagine it's 1980. Someone gives you a cover letter that includes the sentence I showed above. You would probably think they are a showoff. Then again, most would probably take them as a native. That was then. That's not how it goes anymore.

How to Make an AI-Generated Cover Letter Sound Human

Ok, so how do we fix these things? Cover letters need to be official, yet clearly there is a limit in that. The human resources personnel read them daily, and can detect the language better than the average Joe. We humans tend to learn, and just like we learned to walk with two feet, hiring managers have learned to detect subtle nuances in language.

This means that writing a cover letter using AI and swapping out a few words aren't going to cut it. The language is just too strong to be fixed easily. The old tips and tricks that have been going around for years is to have the AI make you bullet points and work from there. In the end, all the sentences are going to be yours. But what's the point in that? Wasn't the idea to literally sit back, relax, and just let an AI write your cover letters?

This is the problem we are trying to tackle. Our cover letter AI check offers a tool to see when it sounds human enough. Making changes, iterating and checking again is a slow-ish yet certain method to make your cover letters pass the HR barrier.

What Recruiters Think About AI-Written Cover Letters?

Well by now this should be clear. Even if your resume and candidacy for the position would be exactly what they are looking for, clearly using an AI shows that you are ready to take the easy way. It really depends on the hiring team, but I think it's safe to say that a cover letter with a soul will do better than a string of words written by a machine. If you let an AI write your cover letter, make it seem like you didn't.