Quick answer: A job description is an internal document that defines a role: duties, responsibilities, reporting line, requirements. A job ad, also called a job posting, is a public message written to get the right people to apply. The description is for your company. The ad is for candidates. Most weak job ads are just job descriptions pasted onto a job board.
What is a job description?
A job description is documentation. It defines what a role is inside your company.
It usually includes:
- Job title and grade or level
- Department and reporting line
- Purpose of the role
- Main duties and responsibilities
- Required qualifications and skills
- Working conditions, like location or travel
- Sometimes pay band and performance measures
It’s used for things that happen after hiring as well: setting pay, performance reviews, contracts, org design and, in some countries, legal disputes about what someone was hired to do. It changes rarely and tends to be formal.
What is a job ad?
A job ad is marketing. It’s written to get the right person to apply and the wrong person to self-select out.
A good one includes:
- A title people actually search for
- What the person will do in their first months, in plain language
- The three to five must-haves
- Pay range
- Location, remote policy and working hours
- What the hiring process looks like
- Why someone would want this job at this company
It’s short-lived. You might rewrite it for every posting and test different versions.
Job ad vs job description: side by side
| Job description | Job ad | |
|---|---|---|
| Audience | HR, managers, the employee | Job seekers |
| Purpose | Define the role | Attract applicants |
| Tone | Formal, complete | Plain, persuasive, specific |
| Length | As long as needed | As short as possible while complete |
| Focus | Duties and requirements | Outcomes, must-haves, why join |
| Language | Company terms (“Level 3 Associate”) | Search terms (“Customer Support Specialist”) |
| Lifespan | Months or years | One posting |
| Includes pay | Often the band | The range candidates will see |
Why does the difference matter?
Because candidates read ads differently from how managers read documentation.
A job description that lists 22 responsibilities tells a candidate nothing about what Tuesday looks like. A requirements list written for HR completeness often scares off good people who meet seven of eight points.
Three common problems when the description is used as the ad:
- Internal titles. Nobody searches for “Associate II, Client Operations”. They search for “account manager”.
- No outcome. Duties tell people what they’d be busy with, not what they’d achieve.
- No reason to apply. A description doesn’t need to sell. An ad does.
How do you turn a job description into a job ad?
Keep the description. Write the ad from it in five steps.
- Change the title to what people search for. See how to choose a job title.
- Write the first two lines as the pitch. What this person will do and why it matters. Most candidates decide here.
- Cut duties to five or six, written as outcomes. “Answer 40 customer chats a day” becomes “Be the person customers reach first, and solve most issues in one conversation.”
- Split requirements into must-haves and nice-to-haves. Three to five must-haves. Label the rest clearly as optional.
- Add the practical details candidates scroll for. Pay range, location, remote policy, hours, process and timeline.
For length, see how long a job description should be. Even though the title says description, it’s about the posting candidates see.
Do you need a job description at all?
For most roles, yes, even a short one.
It anchors the hiring criteria, it helps set pay fairly across similar roles, and it gives the new hire a clear starting point. Small teams can keep it to a page. In bigger companies it’s often part of the job requisition.
There’s also a legal angle in the EU. The Pay Transparency Directive is built around pay for work of equal value, which makes clear, consistent role definitions more important, not less.
What about job description templates?
Templates are a fine starting point for the internal description. They’re a poor starting point for the ad, because templates are generic and the ad’s whole job is to be specific.
We compare the two approaches in JobCraft vs job description templates.
In Canvider, JobCraft drafts the job posting from the role details you give it, and a Job Description Quality Check flags postings that are too thin to publish. You can save descriptions as job templates for roles you hire repeatedly. Edit the draft so it sounds like your team, not like everyone else’s.
A quick test for your current ad
Read the first three lines of your live job ad. If they could appear in a competitor’s ad with only the company name changed, rewrite them.
Try Canvider free. No credit card required.
Frequently asked questions
What is the difference between a job ad and a job description?
A job description is an internal document that defines the role: duties, responsibilities, reporting line, requirements and grade. A job ad, or job posting, is a public message written to attract the right candidates. The description is for HR and managers. The ad is for job seekers.
Can I use my job description as a job ad?
You can, but it usually performs worse. Job descriptions are written as lists of duties in company language. Candidates want to know what they'd actually do, what success looks like, the pay, and why they should pick you. Rewrite the description into an ad.
Is a job posting the same as a job ad?
Yes, in practice. Job posting, job ad, job advert and vacancy notice all mean the public listing candidates see. Job description is the one that usually means the internal document.