The cover letter debate never really ends. Some recruiters say they read every one. Others say they skip straight to the CV. Most job seekers spend hours writing them without knowing which camp the person on the other end falls into.
Here is what the evidence and experience actually suggest, and how to make the decision without overthinking it.
The honest answer
Whether to write a cover letter depends on three things: whether the application requires one, what country or industry you are applying in, and how much you actually have to say.
If the application form has a required cover letter field, write one. This is not optional and skipping it or filling it with placeholder text is an immediate signal that you did not take the application seriously.
If the field is optional, the calculus is more interesting.
When a cover letter genuinely helps
A cover letter helps when you have something specific and relevant to say that your CV cannot communicate on its own.
You are changing industries and your CV looks like the wrong background on paper. A cover letter lets you explain the connection before the recruiter has to figure it out themselves.
You have a gap in your employment history. A single honest sentence addressing it is better than leaving the recruiter to wonder.
You have a genuine connection to the company, the product, or the specific role that goes beyond the generic. Not "I am passionate about innovation" but something that shows you actually know what they do and why you want to work there specifically.
You are applying to a smaller company where the hiring process is more personal. At a startup or a boutique firm, a well written cover letter can matter more than at a large corporation running hundreds of applications through an ATS.
When a cover letter does not help
If you are applying through a large company portal where the first filter is automated, your cover letter may not be read at all until much later in the process. In that situation, the time you spend on the cover letter is better spent tailoring your CV to the job description, because the CV is what the ATS is scoring.
If you genuinely have nothing specific to add beyond what the CV already says, a cover letter that restates your experience in paragraph form adds nothing. Recruiters can tell when a cover letter is filler. It does not hurt you to skip it but a generic one can actually leave a slightly negative impression.
What makes a cover letter worth reading
The cover letters that get read share a few things in common.
They are short. Three paragraphs is enough. The recruiter is not going to read five paragraphs from a stranger before they have even decided to look at the CV.
They open with something specific, not with "I am writing to apply for the position of." Every recruiter has read that sentence ten thousand times. Start with your strongest qualification or your clearest reason for applying to this role at this company.
They include one or two concrete achievements from the CV, not a summary of the entire document. The goal is to make the recruiter want to read the CV, not to replace it.
They close with a direct sentence. Something like "I would welcome the chance to discuss how my background in X applies to what you are building" is more confident and more memorable than a generic closing line.
The format question
Plain paragraphs. No bullet points in a cover letter. No bold headers. No graphics. Just well written prose that sounds like a person wrote it.
Keep it to one page. In most cases, four to six sentences per paragraph and three paragraphs total is the right length.
If you are applying in France or Germany, the tone should be slightly more formal than in Spain, the UK, or the US. The substance is the same but the register matters in those markets.
Using AI to write your cover letter
Using AI to draft a cover letter is fine. Using AI to write a cover letter that sounds like AI wrote it is not, because recruiters recognize the patterns immediately.
The tells are specific: "I am excited to bring my skills to your dynamic team," "I am passionate about leveraging my expertise," anything that sounds like it came from a template. These phrases appear in AI output constantly and flag the letter as generic immediately.
If you use a tool to help, treat the output as a first draft and rewrite it in your own voice. Add a specific detail about the company that only someone who actually read their website would know. Remove any phrase you would not say out loud in a real conversation.
Resumelyn generates cover letters tailored to the specific job description you are applying for. The output avoids the generic phrases that make AI cover letters obvious, and you review and adjust before sending. It is part of the same flow as the CV optimization, so both documents are aligned to the same role at the same time.
The practical decision
If the field is required, write one. If the field is optional and you have something genuine to say, write one. If the field is optional and you have nothing specific to add, skip it and spend that time on your CV instead.
The cover letter that gets read is short, specific, and sounds like a person who actually wants this particular job.