HTTP & Networking
Methods, status codes, caching and TLS explained from first principles. Learn how the web actually moves bytes — and remember it with spaced repetition.
- flashcards
- 98
- flashcards
- per day
- ~10 min
- per day
- level
- Beginner → Intermediate
- level
- modules
- 6
- modules
Why learn HTTP deeply?
HTTP is the protocol every web request, API call and microservice hop runs on — yet most developers know only a handful of its rules by habit. The difference between safe and idempotent methods, why a 301 differs from a 308, or how Cache-Control really decides freshness, quietly shapes how reliable and fast your systems are.
This track grounds the protocol in the specs that define it — methods and semantics, the full status-code families, headers, cookies and caching, and the TLS handshake that turns HTTP into HTTPS — without drowning you in RFC prose.
It also covers how the protocol evolved: connection reuse in HTTP/1.1, multiplexing in HTTP/2, and QUIC in HTTP/3. Spaced repetition turns these details from "I looked that up last week" into knowledge you can reach for mid-debug.
6 modules, seed to bloom
Each module is a set of flashcards — 98 in total. Answer, review, and watch your knowledge grow from seed to full bloom.
HTTP Methods & Semantics
GET, POST, PUT, PATCH, DELETE and the semantics behind safe and idempotent requests
18 cardsStatus Codes
What 2xx, 3xx, 4xx and 5xx status codes mean and when servers return them
17 cardsHeaders, Cookies & Caching
Request and response headers, caching with ETag and Cache-Control, and cookie attributes
18 cardsTLS & HTTPS
How TLS secures HTTP with certificates, key exchange, the handshake, SNI and HSTS
15 cardsHTTP Versions & Performance
How HTTP/1.1, HTTP/2 and HTTP/3 evolved to reduce latency and head-of-line blocking
15 cardsAuth & Sessions
Basic and Bearer auth, cookies versus tokens, JWTs, sessions and CORS basics
15 cardsSample questions
A taste of the real flashcards. Pick an answer, then reveal the explanation.
An endpoint deletes a record when it is fetched with GET. Why is that dangerous?
- AGET is defined as safe, so crawlers and prefetchers will trigger the deletion
- BGET cannot carry a request body, so the record identifier has nowhere to go
- CGET responses are always cached, so the second deletion never reaches the server
- DGET is not idempotent, so a retried request would delete more than one record
What does the 200 OK status code indicate?
- AThe request succeeded and the response carries the result
- BThe request was accepted but processing has not finished yet
- CThe request was redirected to another location to complete
- DThe request failed because the server hit an internal error
What does HTTPS add on top of plain HTTP?
- AA TLS layer that encrypts and authenticates the connection
- BA faster binary framing layer that compresses every header
- CA caching layer that stores responses closer to the client
- DA routing layer that balances traffic across many servers
What did HTTP/1.1 add over HTTP/1.0 for connection reuse?
- APersistent keep-alive connections reused across requests
- BFull request multiplexing over a single shared connection
- CBinary framing that replaced the plain text message format
- DMandatory encryption applied to every request and response
Learn it once, keep it for good
Answer a question
Each card is one practical concept with multiple options. Pick what you think is right.
Get the full answer
See the correct option plus a clear explanation, and a link to deeper docs when one is available.
Review at the right time
A spaced-repetition engine (SM-2 or FSRS) resurfaces each card just before you would forget it.
Why HTTP is worth your time
Foundational for every web role
Frontend, backend, DevOps or security — they all run on HTTP. Deep fluency pays off daily.
Debug faster
Reading status codes, headers and cache behavior correctly turns guesswork into a quick diagnosis.
Build correct APIs
Knowing method semantics and idempotency keeps your APIs predictable and safe to retry.
Interview-ready
HTTP semantics, caching and TLS are perennial favorites in web and systems interviews.
Common questions
Is this just for backend developers? +
No. Frontend, backend, DevOps and security engineers all benefit — HTTP is the shared language of the web.
Does it cover HTTPS and TLS? +
Yes. A full module covers what HTTPS adds, the TLS handshake, certificates and the trust chain.
Is it free? +
Yes, completely free. No registration or credit card is required, and all your progress is stored locally in your browser.
How current is it? +
It reflects the modern HTTP semantics specs and covers HTTP/1.1, HTTP/2 and HTTP/3, so the model matches today's web.
Ready to master HTTP?
Plant your first seed today. Ten minutes a day is all it takes to understand the web from the bytes up.