How to Learn the HTTP Status Codes
Every web request gets a status code back — 200 for success, 404 for not found, 500 for a server error. Knowing the common ones and their categories makes debugging websites and APIs far faster. This deck covers the codes you actually meet.
There are 14 cards in the deck below. You can read through them, practise them right here with the flip-card player, and then save the deck to study properly with spaced repetition — the method that makes them stick for months, not minutes.
Why the HTTP status codes is hard to memorize (and the fix)
There are dozens of codes, but the trick is the categories: 2xx = success, 3xx = redirect, 4xx = your fault (client), 5xx = the server's fault. Learn the pattern and any code makes sense.
The fix is active recall plus spaced repetition. Instead of re-reading the list (which feels productive but barely works), you test yourself — pull each answer out of memory — and you review each card on a schedule that stretches over time. Every time you successfully recall a fact, the memory gets stronger and the next review is pushed further out. That's how you go from "I saw it once" to "I just know it."
The fastest way to learn the HTTP status codes
- Break it into small batches. Learn the four categories first, then the specific must-know codes within each (200, 301, 404, 500).
- Test, don't re-read. Look at the question, say the answer out loud before flipping the card. The little struggle to recall is what builds the memory — a smooth re-read does almost nothing.
- Review on a schedule. Spaced repetition shows you each card right before you'd forget it. Get one right and it comes back in a few days, then a week, then a month. Miss one and it comes back sooner.
- Keep sessions short and daily. Five to ten minutes a day beats a two-hour cram every time. Consistency is the whole game.
One fact per card. Remember the direction of blame: 4xx is the client's fault, 5xx is the server's.
The full deck: the HTTP Status Codes
Here's every card in the set. Practise them above, or save the deck and let spaced repetition schedule your reviews automatically.
| Code | Meaning |
|---|---|
| What does HTTP 200 mean? | OK — the request succeeded |
| What does HTTP 201 mean? | Created — a new resource was made |
| What does HTTP 301 mean? | Moved Permanently (permanent redirect) |
| What does HTTP 302 mean? | Found (temporary redirect) |
| What does HTTP 304 mean? | Not Modified — use the cached version |
| What does HTTP 400 mean? | Bad Request — the request was malformed |
| What does HTTP 401 mean? | Unauthorized — you need to authenticate |
| What does HTTP 403 mean? | Forbidden — you are not allowed |
| What does HTTP 404 mean? | Not Found |
| What does HTTP 500 mean? | Internal Server Error |
| What does HTTP 503 mean? | Service Unavailable (server overloaded or down) |
| What do 2xx codes mean? | Success |
| What do 4xx codes mean? | Client errors (your request was wrong) |
| What do 5xx codes mean? | Server errors |
Save this deck and actually remember it
Create a free account, keep this 14-card deck, and we'll schedule every review at the perfect moment. First deck free forever — no credit card.
Study this deck free →FAQ: learning the HTTP status codes
How long does it take to learn the HTTP status codes?
Most people can lock in the HTTP status codes within one to three weeks of short daily sessions. With spaced repetition doing 10–14 cards a day, you'll recognise them within days and recall them reliably within a couple of weeks.
What's the best way to memorize the HTTP status codes?
Active recall plus spaced repetition. Test yourself instead of re-reading, and review on a schedule that spaces the cards out over time. Flashcards are built for exactly this — which is why the deck above is the fastest path.
Is this deck free?
Yes. You can practise all 14 cards on this page for free with no account. Sign up (also free) to save the deck and let spaced repetition schedule your reviews so it sticks long-term.