How to Write Technical Documentation With Code Examples

Write for the Reader Who Is Already Frustrated

Most people arrive at technical documentation after something has broken or refused to work. They are not reading for pleasure. That means your first job is to orient them fast — what does this doc cover, what does it assume, and what will they be able to do at the end. One short paragraph at the top does that. Skip it and you lose half your readers in the first thirty seconds.

Avoid long introductions that describe the history of the library or why the team built it. That belongs in a blog post. Documentation is a reference tool first. Treat it like a map, not a memoir.

Code Examples Do the Heavy Lifting

Prose explains concepts. Code examples prove them. A developer reading about an API call will skim your paragraph and paste your code block. That means every example needs to actually run. Copy it out, try it fresh, and confirm it produces the output you claim. Broken examples destroy trust faster than any amount of bad prose.

Keep examples minimal but complete. Strip out unrelated setup that forces a reader to guess what variables to define. If the function takes three arguments, show all three with realistic values — not `foo`, `bar`, and `baz`. Show what the output looks like too. A comment like `// returns: { status: 200, user: {...} }` saves a developer from running the code just to see the shape of the response.

When you need to show a longer workflow — authentication, then a request, then error handling — break it into stages with a short sentence bridging each block. Reading a wall of code with no signposts is exhausting even for senior engineers.

Structure Every Page the Same Way

Consistency is a form of respect for your reader's time. When every page in your docs follows the same pattern — overview, prerequisites, code example, common errors — a developer can skip straight to the section they need without scanning the whole page. Surprise structure forces them to read everything, which they will not do.

A reliable page template: one-sentence description of what the function or endpoint does, prerequisites or imports needed, a minimal working example, a table of parameters with types and defaults, and a section on errors or edge cases. That order works for most reference pages. Stick to it.

Treat Error Messages as First-Class Content

The most searched phrase in any developer docs is an error message. If your documentation never mentions what happens when something goes wrong, every error becomes a dead end. Add a dedicated section — or at minimum inline callouts — for the errors a user is likely to hit and exactly what causes each one.

Copy the actual error string. Developers paste errors into search; if your docs use a paraphrase, Google will not connect the two. Then explain what the error means, what usually causes it, and how to fix it. That sequence — meaning, cause, fix — is the fastest path from broken to working.

Frequently asked questions

How long should a technical documentation page be?

Long enough to cover the topic completely, short enough to scan in under two minutes. If a page needs more than four or five sections, consider splitting it. Readers should be able to find what they need without scrolling past unrelated content.

Should code examples use real or dummy values?

Use realistic dummy values — things like `user_id: 42` or `api_key: 'YOUR_API_KEY_HERE'` rather than `x` or `foo`. Realistic values make the context obvious and reduce the cognitive load of figuring out what a variable is supposed to represent.

How often should technical documentation be updated?

Every time the code it documents changes. Stale docs are worse than no docs because they send developers down wrong paths confidently. Treat doc updates as part of every pull request that changes public behavior.

What is the best way to show multiple programming languages in docs?

Use tabbed code blocks if your tooling supports them. Show the most common language first. Don't try to cover every language — pick two or three that match your actual user base and do those well rather than giving eight mediocre examples.