Reverse a cipher
API · /cipher-api
Cipher API
healthy
4,732 Subscribers
Encode and decode classical ciphers and alphabets as an API — Morse code, ROT13, the Caesar shift (with any shift 1-25), Atbash, the NATO phonetic alphabet, leetspeak, A1Z26 (letters to numbers) and string reversal. Send text and a cipher and get the transformed string back, or decode it again — most are perfectly reversible. Everything runs locally, so it is fast and always available. Ideal for puzzle and escape-room games, ARGs, treasure hunts, education and coding lessons, retro and hacker-themed UIs, and chat bots. For base64/hex/URL encodings use the Encoding API; for cryptographic hashes use the Hash API.
api.oanor.com/cipher-api
API health
healthy- Uptime
- 100.00%
- Server probes · 24h
- Avg latency
- 72 ms
- Server probes · 24h
- Subscribers
- 4,732
- active
- Total calls
- 76
- last 7 days
Pricing
Pick a tier — billed monthly, cancel anytime.
Free
Free
- 16,000 calls / month
- 2 requests / second
- Hard cap (429 above quota, no overage)
- 16,000 calls/month
- 2 req/sec
- 8 ciphers, encode & decode
- No credit card
Starter
€2.40 /month
- 235,000 calls / month
- 8 requests / second
- Hard cap (429 above quota, no overage)
- 235k calls/month
- 8 req/sec
- Caesar shift control
- Email support
Pro
€8.30 /month
- 920,000 calls / month
- 20 requests / second
- Hard cap (429 above quota, no overage)
- 920k calls/month
- 20 req/sec
- Games & education apps
- Priority support
Mega
€27.60 /month
- 3,800,000 calls / month
- 50 requests / second
- Hard cap (429 above quota, no overage)
- 3.8M calls/month
- 50 req/sec
- Bots & high-traffic apps
- Dedicated SLA
Built by
Related APIs
Other APIs with overlapping tags.
Morse Code API
Morse code conversion as an API, computed locally and deterministically. The encode endpoint turns text into International Morse code, mapping A–Z, the digits 0–9 and common punctuation to dots and dashes, separating letters with a space and words with a slash, and listing any unsupported characters it skipped. The decode endpoint turns Morse code back into text, accepting word separators written as a slash, a pipe or a wide gap, and marking unrecognised symbols. The timing endpoint computes the PARIS-standard timing from a words-per-minute speed — the dot duration is 1200/WPM milliseconds, a dash is three dots, and the gaps are one, three and seven dot units for intra-character, inter-character and word spacing — and, given a Morse message, the total number of units and the transmission time. The word PARIS is exactly 50 units, which defines the WPM scale. Everything is computed locally and deterministically, so it is instant and private. Ideal for amateur-radio, aviation, education, accessibility, puzzle and game app developers, signalling and CW-training tools, and learning Morse. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is Morse code; for Base64 and JWT use an encoding API and for Caesar and substitution ciphers a cipher API.
api.oanor.com/morse-api
Duolingo Profile & Streak API
Live public profile and language-learning stats from Duolingo, the world's largest language-learning platform — no key, nothing stored. This is the gamified-learning social view: a learner's XP, daily streak, courses and progress, distinct from every other social platform in the catalogue. The user endpoint returns a profile summary — display name, bio, location, join date, total XP, the current daily streak, the language being learned and the from-language, the current course, Super/Plus status and a course count. The courses endpoint returns the per-language breakdown: every course the learner studies with its title, learning and from languages, XP earned and crown count. The streak endpoint returns the streak detail — the current streak length and, when the learner makes it public, the streak start date and longest streak. Lookup is by username; the official mascot account "duo" is always available. Build streak widgets, learning-accountability bots, language-club leaderboards and profile cards on top of real Duolingo data. Private or non-existent usernames return a clean 404.
api.oanor.com/duolingo-api
College Majors API
Earnings and employment outcomes for 170+ US college majors, from FiveThirtyEight's analysis of the U.S. Census American Community Survey. For each major: its category (Engineering, Business, Arts…), number of graduates and share who are women, median / 25th- / 75th-percentile earnings of full-time workers, unemployment rate and college-job counts. Look a major up by name or code, list a category, rank majors by earnings or unemployment, or search. Ideal for edtech, career-guidance, student-advising and HR analytics apps.
api.oanor.com/collegemajors-api
Flags API
National flag design as an API — built on the classic UCI "Flags" dataset (194 countries) and enriched with each country's ISO 3166-1 alpha-2 code, its Unicode flag emoji and ready-to-use SVG / PNG image URLs. For each flag the API exposes its real design attributes: the number of vertical bars and horizontal stripes, the colours present, the predominant ("main") hue, the colours of the top-left and bottom-right corners, and which symbols appear — circles, crosses, saltires, quartered fields, stars or suns, a crescent, a triangle, an inanimate icon (e.g. an anchor), an animate image (e.g. an eagle) or written text. Look a flag up by country or code, search, or FILTER flags by colour, main hue or symbol — "every flag with a crescent", "flags that are mainly green". Served from memory — always fast.
api.oanor.com/flags-api
Frequently asked questions
Quick answers about pricing, quotas, and integration.
How do I get an API key for Cipher API?
Sign up for free at oanor.com, generate an API key from the developer dashboard, and call Cipher API with the x-oanor-key header. No credit card needed for the free tier.
What's the rate limit for Cipher API?
Free tier allows 1 request per second. Paid plans scale up to 50 requests per second on the Mega tier. Hard limits return HTTP 429 above the quota — no surprise overage charges.
How much does Cipher API cost?
Cipher API has a free tier with 100 calls / month. Paid plans start at €2.40 / month with higher quotas and faster rate limits.
Can I cancel my subscription anytime?
Yes. Plans are billed monthly and you can cancel anytime from your billing dashboard. No long-term contracts and no cancellation fee.
Is Cipher API GDPR-compliant?
All requests to Cipher API go through our EU-based gateway. Your upstream API key never leaves our server and no personal data is shared with the upstream provider beyond the request you send.
Pick an endpoint from the list on the left to see its details and try it.
Code snippets
Sign up to get an API key, then call any path under your slug.
curl https://api.oanor.com/cipher-api/SOME_PATH \
-H "x-oanor-key: oanor_test_..."const res = await fetch("https://api.oanor.com/cipher-api/SOME_PATH", {
headers: { "x-oanor-key": "oanor_test_..." }
});
const data = await res.json();$ch = curl_init("https://api.oanor.com/cipher-api/SOME_PATH");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
$response = curl_exec($ch);import requests
r = requests.get(
"https://api.oanor.com/cipher-api/SOME_PATH",
headers={"x-oanor-key": "oanor_test_..."},
)
print(r.json())Ratings
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