The short answer
Write one when the application asks for it, when the role is one you really want, or when your resume leaves an obvious question unanswered. Skip it when the form has no place for one and the job is a close, ordinary match for your experience. In between, a short letter rarely hurts and sometimes helps.
There's no reliable figure for how many recruiters read cover letters; surveys disagree and depend on who's asked. What's consistent is that the people who do read them read them for a specific reason, and a letter written to that reason is worth far more than a generic one.
When a cover letter matters
A letter earns its place when it tells the reader something the resume can't:
- The posting asks for one. "Required" means required; an application without one is often screened out before anyone reads the rest.
- You're changing careers. The resume shows where you've been; the letter explains why that experience fits where you're going.
- There's a gap, a move or a step down. One plain sentence answers the question before it's asked.
- The company is small or the hiring manager reads applications personally. Small teams hire people, not keyword matches.
- The role is a stretch. A letter can connect two or three things you've done to what the job actually needs.
- You have a real connection: a referral, a product you've used for years, a problem you've worked on that they have.
When you can skip it
If the application form has no upload or text box for a letter, don't force one in elsewhere. If it's optional, the job is a straightforward match, and you're applying to many similar roles, a strong tailored resume matters more than a letter. Time is finite; spend it where it changes the outcome.
What a good one looks like
Under a page, and usually 200 to 300 words. Three or four short paragraphs are plenty:
- Why this role at this company, specifically. Not "I am writing to express my interest"; that line is in every letter and tells the reader nothing.
- Two or three things you've done that match what the posting asks for, each with what changed because of it.
- Anything the resume leaves open: the career change, the gap, the relocation.
- One closing sentence about next steps. No need for "I look forward to hearing from you at your earliest convenience".
Writing one in fifteen minutes
Keep a base letter with your strongest two or three stories, written once and well. For each application, rewrite the first paragraph from scratch for the company, pick the stories that match the posting, and use the posting's own words where they describe what you did. Read it out loud; anything you wouldn't say to the hiring manager's face comes out.
An AI generator can do the first draft, as long as it only uses facts you gave it and you edit the result into your own voice. Recruiters don't mind a letter being drafted with help; they mind a letter that could have been sent to any company.
An opening that works
The first two lines decide whether the rest is read. Compare two openings for the same job, a support operations role at a software company:
Generic: "I am writing to express my interest in the Support Operations Manager position at your company. I believe my skills and experience make me an excellent candidate."
Specific: "Your posting says the support team is moving from email to in-app chat this year. I ran that same move at my last company, for a team of twelve, and I'd like to do it again with you."
The second one names something from the posting, connects it to something the writer actually did, and makes the reader want the next paragraph. It took one careful read of the posting to write.
Common mistakes
- Repeating the resume line by line. The letter is for the reasons and the connections, not the list.
- Writing about what the job will do for you. Say what you'll do for them.
- The wrong company name. It happens more than you'd think when letters are reused; check it last, every time.
- Adjectives with nothing behind them: "passionate", "dynamic", "results-driven". Replace each with the thing you did.
Questions
Do recruiters actually read cover letters?
Some do and some don't, and it varies by company and role. Small companies, career changers' applications and roles that require a letter are where they're read most. Since you can't tell in advance, a short, specific letter is the safe choice for jobs you care about.
Should I write a cover letter if it's optional?
For roles you really want, yes, if it's short and specific. For close, ordinary matches where you're applying widely, a well-tailored resume is the better use of the time.
How long should a cover letter be?
Under one page, usually 200 to 300 words in three or four short paragraphs.
Is it OK to use AI to write a cover letter?
Yes, for a first draft, as long as it only uses facts you provide and you edit it into your own voice. Check every claim in it is true before you send it.