How long should a case study be?

Between 400 and 800 words for most service businesses. Long enough to show the work, short enough that a prospect reads it before a call. If you need more room, add a short summary box at the top so skimmers still get the outcome.

What are the sections of a case study?

Headline, Challenge, Solution, Results, Why it matters, and a Customer quote. That order matches the questions a prospect asks in their head: is this like me, how did they do it, did it work, can I believe it.

What if my client cannot share numbers?

Use observable change instead: hours saved per week, a process that used to take three people, a backlog that cleared. Never invent a figure. A qualitative case study with an honest quote outperforms an invented statistic that a prospect can question on a call.

Do I need the client's permission to publish a case study?

Yes. Get explicit, written permission naming what will be published, their name, company, logo, and the specific figures. Keep the record. Anonymised case studies are an option when a client cannot be named, but the permission still has to be asked for.

How do I write a case study fast?

Collect the answers in a structured way rather than a free-form chat, so you are editing instead of starting from a blank page. CasePruve does this with one link: your client answers the five questions, and the answers are turned into the six sections, plus a post and a thread you can publish the same day.

Guide

How to write a case study

The structure, the questions to ask, and the mistakes that make a case study unreadable. Everything here works with a notepad, the tool at the end is optional.

1. Interview before you write

A case study is only as good as the raw material. Ask five questions: what was happening before, what you did, what changed, one number they can share, and what they would tell someone considering the same work. Record the answers in their words, you will use those words later.

Ask right after a visible win, while the result is still fresh.
Push gently for one concrete figure, and accept a range if that is all they have.
Never write the quote for them, approve, do not invent.

2. Pick one result, not five

Every strong case study is about a single outcome. If the project touched six things, choose the one your next client cares about and let the rest be context. A case study that tries to prove everything proves nothing.

Write the outcome as a sentence before writing anything else.
If you cannot state the outcome in one line, you are not ready to write.

3. Write the six sections in order

Headline, Challenge, Solution, Results, Why it matters, Customer quote. This order matches how a prospect reads: they check whether the situation sounds like theirs, then how you solved it, then whether it worked.

Headline: the outcome plus the client type, no adjectives.
Challenge: the before state, in the client's language.
Solution: what you actually did, in plain steps.
Results: numbers or observable change, sourced from the client.
Why it matters: why this result is hard, in two sentences.
Quote: verbatim, attributed, with permission.

4. Keep every claim traceable

For each sentence in Results, you should be able to point at the line in the interview it came from. If you cannot, cut it. This is the difference between a case study a prospect trusts and marketing copy they skim.

Attribute figures to the client, not to yourself.
Say what you measured and over what period.
Get written approval of the final text before publishing.

The outline, ready to fill in

Copy this into your notes and replace the brackets. If a section is empty, you are missing an answer from your client, not a sentence from yourself.

Headline
[Outcome] for [client type] in [timeframe]

Challenge
Where the client was before, in their words. What it was costing them.

Solution
What you did, in three to five plain steps.

Results
The change, with at least one figure the client confirmed.

Why it matters
Why this result is not trivial, in two sentences.

Customer quote
"Verbatim quote.", Name, Role, Company

Want more formats? See the free case study templates or the customer success story template.

Six mistakes to avoid

Opening with your company story instead of the client's problem

Vague results: "significantly improved" instead of what actually changed

Quotes that sound written by a marketer, not said by a person

Burying the outcome three paragraphs down

Publishing before the client has approved the exact wording

One case study for every audience, instead of one per client type

Questions people ask

Or skip the blank page

Send your client one link. They answer the same five questions, and CasePruve builds the six sections from their words, plus a post and a thread you can publish the same day.

Start free See published examples

Not ready to create a link yet?

Get the 5-day Proof Playbook: the exact asks, follow-ups and posts we use to turn one happy client into content that sells.

A few useful emails, no spam. Unsubscribe anytime. See our privacy policy.