Free cover letter tools
A cover letter earns its place when it says something the resume cannot: why this company, what you understood about the problem they're hiring against, and what you would do in the first month. Most letters fail because they restate the resume in longer sentences.
Length is where people lose the reader. Somewhere between 250 and 350 words is enough to make one specific argument well. Past that, the reader starts skimming and the specifics you worked hardest on disappear into the middle paragraphs.
Write the opening paragraph last. It's much easier to open well once you know what your argument actually turned out to be.
The tools
A structure that holds up
Open with the specific reason you're writing to this company rather than a summary of yourself. Second paragraph, the single strongest piece of evidence that you can do the work, ideally the same achievement your resume lists but with the context the bullet had no room for. Third, what you'd want to understand or work on first. Close with one line and your name.
That's four short paragraphs and it's enough. The instinct to add a fifth is almost always the instinct to restate something you already said.
When a cover letter is worth writing
When it's optional and you have something specific to say, write it. When it's optional and you'd be producing filler, skip it and put the time into tailoring your resume instead, which has a larger effect. When it's required, treat the requirement as a filter: plenty of applicants will submit something generic, so a letter with one concrete, verifiable claim in it stands out cheaply.
Career changers get the most out of cover letters, because a resume alone rarely explains why the switch makes sense. That explanation is exactly the thing the format is good at.
Things that quietly cost you
Addressing it to the wrong company is more common than you'd think and is fatal, so check the name before sending if you reused a draft. Beyond that: opening with "I am writing to apply for", listing adjectives about yourself with no evidence attached, and explaining why the role would be good for you rather than what you'd contribute.
Related guides
Common questions
How long should a cover letter be?
Between roughly 250 and 350 words. That's enough to make one specific argument properly. Past that, readers skim and the specifics you worked hardest on get lost in the middle.
Do recruiters actually read cover letters?
It varies enormously by company and by role. Assume it may not be read, which argues for making the first two sentences carry your strongest point rather than saving it for the end.
Can I reuse one cover letter?
You can reuse the structure and your core evidence. Rewrite the opening and any sentence naming the company. A letter that could have been sent to anyone reads exactly like one that was.
Other tool sets: Interview prep · Resume tools · Salary and offers · Job search · Recruiter outreach · Free utilities