HTTP Status Codes
Codes and their meaning
Qardbox is a free flashcard app for iPhone, iPad and Apple Watch, with no ads and with your data staying yours. It costs nothing, asks for no account and shows no ads, and your own cards stay unlimited. That is a promise.
You can always create as many flashcards as you like, free of charge.
This deck costs you nothing. You get 42 flashcards, sorted into 5 categories and with notes that add to them. You start out learning instead of typing, and whatever you find missing later you add yourself.
- Cards
- 42
- Categories
- 5
- Price
- free
Free, no account, no ads
What is in this deck
With this deck you learn the HTTP status codes that come up in practice: from 200 through 301 and 404 to 503, each with its meaning.
401 or 403? The difference tells you where to look: one is a missing login, the other insufficient rights.
This deck covers 42 status codes, from 100 Continue to 511. The names stay English because that is how they appear in the protocol and in every server log. Notes appear only where something needs distinguishing: 301 against 308, 502 against 504, and explain where 418 and 451 get their numbers.
The codes follow RFC 9110 and the IANA registry.
The categories decide what comes up: start with “1xx Informational” alone and add the rest when you are ready.
What you learn
- 42 status codes from 100 to 511
- 401 vs 403, 301 vs 308, 502 vs 504
- Where 418 and 451 got their numbers
The categories
5 categories sort the 42 cards. You can filter by category and take on what is due right now.
- 1xx Informational
- 2xx Success
- 3xx Redirect
- 4xx Client
- 5xx Server
What you get
Here are three of the 42 cards that are in this deck.
Question
What does HTTP status 100 mean?
Answer
Continue
Note
Question
What does HTTP status 101 mean?
Answer
Switching Protocols
Note
Question
What does HTTP status 200 mean?
Answer
OK
Note
Learning with Qardbox
You see a card, you think, you turn it over and say whether you knew it. A round asks nothing more of you, and how the app works out the next date from that is on the page about FSRS-6.
What sits comes back less often, what wobbles comes back soon. You set a daily goal, and when nothing is due the app tells you exactly that instead of inventing work for you. How a round goes is shown on the learning page.
Everything stays on your device. No account, no sign-up, no ads. After the purchase the deck sits in your library like any other subject and can be studied, reordered and extended just like your own.
What it costs, and what it doesn’t
Qardbox itself costs nothing, and it stays that way. Every function is there from the start, with no subscription, no ads and no tiers; what that rests on is on the page about what it costs.
Your own cards stay unlimited, and decks from friends or from the family you read in without a limit, from a file as well. You do not need this deck in order to learn with Qardbox.
This deck costs nothing. Its 42 cards are checked and save you the work you would otherwise have.
Common questions
Do I have to pay for Qardbox?
No. The app is free, with no subscription and no ads, and every function is there. This deck is free too; some other ready-made decks cost a little, once.
Could I make these cards myself?
Yes, without limit and for free. You can type them, import a file or take over cards from friends. This deck only saves you the work.
How many cards are in HTTP Status Codes?
42 cards, sorted into 5 categories.
Do I need a connection to study?
Only to download the deck. After that it lives on your device and you study offline. There is no account, and you sign in nowhere.
Which devices does this run on?
On iPhone and iPad from iOS 26, and on Apple Watch. One purchase covers the family through Family Sharing.
Is there a Qardbox for Android?
No. Qardbox is there for iPhone, iPad and Apple Watch, not for Android and not in a browser.
Other decks that go with this one
Get started
Get Qardbox, look at the deck in the store and decide there. The app is free whether you take this deck or not.
Free on the App Store, no account.