#dev-tools

A fast, fully-local astronomy and ephemeris engine: compute the equatorial (right-ascension/declination) and horizontal (azimuth/altitude) positions of the Sun, Moon and all planets for any observer and moment, get precise rise, set and transit (culmination) times for any body, read detailed lunar state (phase angle, named phase, illuminated fraction, apparent magnitude, geocentric distance, age since the last new moon and the dates of the next new/first-quarter/full/last-quarter moons), and list the exact equinoxes and solstices of any year. Every endpoint accepts input via the query string or the request body. Pure server-side computation (no third-party upstream), so responses are instant and always available. Ideal for weather and tide apps, astrophotography planners, calendars, solar/energy tools, Islamic and lunar calendars, and education.

api.oanor.com/astronomy-api

Work with geohashes through a fast, fully-local API. Encode a latitude/longitude pair into a geohash at any precision (1–12), decode a geohash back to its centre coordinates with the exact bounding box and error margins, list the eight neighbouring geohash cells (north, north-east, east and so on), or get the bounding box, centre and dimensions of a cell. Geohashes turn coordinates into short sortable strings that are perfect for spatial indexing, proximity grouping and map tiling. Pure server-side computation with no third-party upstream, so responses are instant and the service is always available. Ideal for geospatial indexing and search, proximity and nearby queries, map tiles and clustering, IoT and fleet tracking, and location bucketing in databases.

api.oanor.com/geohash-api

Hash and verify passwords with bcrypt, server-side. Generate a salted bcrypt hash at a cost factor you choose (4–14), check a plaintext password against an existing hash, or inspect a hash to read its bcrypt version, cost factor and salt. Fully compatible with bcrypt hashes from PHP ($2y$), Node, Python and others, so you can verify and migrate existing credentials. Pure server-side computation with no third-party upstream, so it is always available — and it offloads the deliberately CPU-intensive hashing work from your own servers. Ideal for adding password authentication, credential migration, auth tooling, testing and no-code backends.

api.oanor.com/bcrypt-api

Python package data from PyPI as clean JSON. Look up any package’s latest metadata — version, summary, license, repository, author, keywords, required Python version, dependencies, supported Python versions and total release count — browse its full version history with release dates and yanked flags, or get the details and distribution files for one specific version. Sourced live from the public Python Package Index and returned through a fast, reliable API. Ideal for developer dashboards and tooling, package and dependency analytics, security and supply-chain checks, CI/CD and documentation sites.

api.oanor.com/pypi-api

Identify the manufacturer behind any MAC address. Look up a MAC or OUI to get the assigned vendor, its short name and the exact assignment block (/24, /28 or /36) using the official IEEE registry, search the registry by vendor name to find all of a company’s OUIs, or generate random valid test MAC addresses for a given vendor. MAC addresses are accepted in every common format — colon, hyphen, dot or bare hex — and bare OUIs work too. Built on the open IEEE OUI dataset (~57,000 assignments) and served entirely in-memory, so responses are instant and the service is always available. Ideal for network scanning and monitoring, IoT and device identification, security and asset inventory, NAC and devops tooling.

api.oanor.com/macvendor-api

Parse any hostname or URL with the Public Suffix List. Split a domain into its subdomain, registrable domain (eTLD+1) and public suffix (eTLD), or fetch just the suffix or just the registrable domain. Handles full URLs, internationalized (punycode) domains, IP addresses, multi-level suffixes like co.uk and com.au, and — when you ask for it — private suffixes such as github.io and s3 buckets. Built on an always-current Public Suffix List and served entirely in-memory, so responses are instant and the service is always available. Ideal for cookie and domain scoping, analytics attribution, email and link validation, security and anti-abuse, and devops tooling.

api.oanor.com/domain-api

Stopword lists and removal for 58 languages. Fetch the full stopword list for a language, see all supported languages with their word counts, check whether a single word is a stopword, or strip stopwords out of a block of text to get a clean keyword stream. Built on the open stopwords-iso dataset and served entirely in-memory, so responses are instant and the service is always available. Ideal for search indexing and relevance, NLP preprocessing and text mining, keyword extraction, tag generation and content tooling.

api.oanor.com/stopwords-api

Everything about npm packages in one clean API. Look up a package’s latest metadata — version, description, license, homepage, repository, author, keywords, dist-tags, dependencies and maintainers — list its full version history with release dates, pull download statistics for the last day, week, month or year, and search the registry across more than three million packages. Sourced live from the public npm registry and returned as tidy JSON through a fast, reliable API. Ideal for developer dashboards and tooling, package and dependency analytics, supply-chain and security checks, CI/CD and documentation sites.

api.oanor.com/npm-api

Query and extract from JSON with JSONPath, server-side. Run any JSONPath expression — wildcards, recursive descent, array slices and filter expressions like [?(@.price>10)] — against a JSON document and get back the matched values, the normalized paths and JSON Pointers of every match, or just the first match. Filter expressions are evaluated in a safe sandbox with no access to globals, and inputs can be sent as a JSON POST body or a query parameter. Pure local compute with no third-party upstream, so responses are instant and the service is always available. Ideal for no-code and automation platforms, ETL and data pipelines, API integrations, testing and config extraction.

api.oanor.com/jsonpath-api

Convert, validate and tidy YAML through a fast, fully-local API. Turn YAML into JSON (including multi-document streams) or JSON into clean YAML with optional key sorting and custom indentation, validate a document and get the exact line and column of any syntax error with a context snippet, or reformat and normalize existing YAML. Inputs can be sent as a raw text/plain body, a JSON field or a query parameter; outputs are tidy JSON. Pure server-side compute with no third-party upstream, so responses are instant and the service is always available. Ideal for DevOps and CI/CD, configuration and infrastructure-as-code tooling, no-code platforms, editors and data pipelines.

api.oanor.com/yaml-api

Validate JSON against JSON Schema, server-side. Check any data against a schema (Draft-07 or 2020-12) and get a clear pass/fail plus a detailed list of every error with its instance path, failing keyword and message; verify that a schema itself is well-formed; or infer a starter JSON Schema automatically from a sample document, complete with detected formats like email, URI and date. Built on the battle-tested Ajv engine with full format validation. Every endpoint accepts GET (JSON-encoded parameters) or a JSON POST body and runs entirely locally with no third-party upstream, so responses are instant and the service is always available. Ideal for API request/response validation, form and data-entry checks, ETL and data-quality pipelines, no-code platforms and contract testing.

api.oanor.com/jsonschema-api

Run regular expressions server-side without the ReDoS risk. Test whether a pattern matches, extract all matches with their positions and capture groups (numbered and named), replace with a substitution pattern, or split text — all with the familiar JavaScript regex flags (g, i, m, s, u, y). Every evaluation runs in an isolated sandbox with a hard timeout, so a catastrophic-backtracking pattern can never hang your service; you get a clear timeout error instead. Inputs accept GET query parameters or a JSON POST body. Pure local compute with no third-party upstream, so responses are instant and the service is always available. Ideal for no-code and automation platforms, data-cleaning pipelines, form and input validation, log parsing and content tooling.

api.oanor.com/regex-api

Compare two pieces of text and get a precise, structured diff. Choose line, word or character granularity for a full edit script (equal, inserted, deleted) with addition and deletion counts, get a compact inline word diff, or render a standard unified diff (patch) with configurable context lines and file labels — ready to feed into patch tooling or a code-review UI. Built on a Longest-Common-Subsequence algorithm for accurate, minimal diffs. Every endpoint works by GET or JSON POST and runs entirely server-side with no third-party upstream, so responses are instant and the service is always available. Ideal for code review and version tooling, CMS and document editors, change tracking, plagiarism highlighting and content audits.

api.oanor.com/textdiff-api

A fast, fully-local SVG generator for mockups and UIs: placeholder images (a sized rectangle with centered text and automatic contrast), initials avatars (with a deterministic colour derived from the name, in a circle or square), and identicon-style symmetric patterns generated deterministically from any seed. Every endpoint returns the JSON envelope or, with raw=1, the raw SVG so the URL can be used directly as an image source. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for prototypes, dashboards, user avatars, empty states and design systems.

api.oanor.com/placeholder-api

A fast, fully-local dice toolkit for games and simulations: roll dice notation (NdM with plus and minus modifiers, multiple dice terms like 1d8+1d6+2, and keep-highest or keep-lowest for advantage and disadvantage such as 2d20kh1), parse and validate a notation, and compute the deterministic minimum, maximum and mean of a roll. Rolls use a cryptographically secure random source. Every endpoint accepts input via the query string or the request body. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for tabletop and RPG tools, Discord and chat bots, virtual tabletops and game backends.

api.oanor.com/dice-api

A fast, fully-local cron-expression toolkit (UTC): validate 5-field cron expressions with ranges, lists, steps, month and weekday names and the common @aliases (@yearly, @monthly, @weekly, @daily, @hourly); compute the next N run times for a schedule from now or any start date; and describe a schedule in plain English. Every endpoint accepts input via the query string or the request body. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for schedulers and job runners, devops and CI tooling, and dashboards that show the next run time of a task.

api.oanor.com/cron-api

A fast, fully-local JSON Web Token toolkit: sign a JSON payload into a JWT, verify a token signature together with its exp and nbf claims using a constant-time comparison, and decode a token header and payload without verifying. Supports the HMAC algorithms HS256, HS384 and HS512, automatically adds the iat claim and an exp claim from expires_in. Built on Node crypto and secrets are never logged, so responses are instant, private and always available. Every endpoint accepts input via the query string or the request body. Ideal for authentication, API gateways, session and token tooling, microservices and webhooks.

api.oanor.com/jwt-api

A fast, fully-local identifier-generation toolkit: create UUID v4 (random), v7 (time-ordered and lexicographically sortable), v3 and v5 (name-based, deterministic via MD5 and SHA-1 over a namespace plus name) and the nil UUID; generate ULIDs (sortable, Crockford base32); generate nanoids (URL-safe, with custom alphabet and size); and validate any UUID, reporting its version and variant. Every endpoint accepts input via the query string or the request body. Built on Node crypto, no third-party upstream, so responses are instant and always available. Ideal for databases and primary keys, distributed systems, idempotency and correlation keys, and general developer tooling.

api.oanor.com/uuid-api

A fast, fully-local MIME and file-type toolkit: look up the MIME type, charset and category for a filename or extension, list every file extension registered for a MIME type, and detect a file's real type from its leading magic bytes (over 40 signatures, including RIFF container disambiguation for WEBP, WAV and AVI), accepting hex or base64 input. Every endpoint accepts input via the query string or the request body. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for upload validation, security (verify a file's real type against its claimed extension), CDNs and content pipelines.

api.oanor.com/mime-api

A fast, fully-local number toolkit: spell numbers out in English words (great for amount-in-words on invoices and cheques), format ordinals (1st, 2nd, 112th), convert integers to and from Roman numerals (1 to 3999), convert numbers between any bases from 2 to 36, and format numbers locale-aware as decimal, currency or percent. Every endpoint accepts input via the query string or the request body. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for invoicing and billing, localization, education and developer formatting tooling.

api.oanor.com/number-api

A fast, fully-local IP and subnet calculator: validate IPv4 and IPv6 addresses with type classification (private, public, loopback, link-local, multicast, CGNAT or reserved), compute CIDR subnet details (network, netmask, wildcard, broadcast, first and last host, total addresses and usable hosts, with IPv6 network and range size), check whether an address falls inside a CIDR block, and convert addresses (IPv4 to integer, hex and binary; IPv6 expand and compress). Every endpoint accepts input via the query string or the request body. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for devops, network automation, IPAM, firewall and ACL tooling and cloud infrastructure.

api.oanor.com/subnet-api

A fast, fully-local CSV data toolkit: parse CSV into typed row objects (RFC-4180), compute per-column statistics (count, unique, type and top values, and for numeric columns min, max, mean, median and sum), remove duplicate rows by all or a subset of columns, sort by a column with numeric-aware ordering, and filter rows by a condition (equals, not-equals, greater/less than, contains, starts-with, empty, not-empty). Every endpoint accepts input via the query string or the request body, up to 2 MB, and returns both row objects and a CSV string. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for data wrangling, ETL, analytics preparation, spreadsheet tooling and data cleaning. (For plain CSV to JSON conversion, see the oanor JSON API.)

api.oanor.com/csv-api

A fast, fully-local XML toolkit: convert XML to JSON and JSON to XML with configurable attribute handling, validate XML well-formedness with line and column error details, and pretty-print XML while preserving element order. Every endpoint accepts input via the query string or the request body, up to 2 MB. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for system integrations, SOAP and legacy interop, RSS and sitemap processing, config tooling and data pipelines.

api.oanor.com/xml-api

A fast, fully-local HTML toolkit: extract structured data from supplied HTML (title, meta description, canonical link, language, Open Graph and Twitter card tags, links, images, headings and word counts), convert HTML to readable plain text, list all links resolved against a base URL, and sanitize HTML with a strict allowlist (scripts, iframes, inline event handlers, javascript: URLs and unknown tags are stripped). It works on the HTML you send and never fetches URLs (for live link previews see the oanor URL Tools API). Input via the query string or the request body, up to 2 MB. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for scrapers and data pipelines, comment and email sanitization, RAG and content extraction, and CMS tooling.

api.oanor.com/html-api

A fast, fully-local date and time toolkit (UTC): parse any date string or unix timestamp into ISO, unix and components with the ISO week number, day-of-year and leap-year flag; format dates with custom tokens (YYYY-MM-DD, weekday and month names, and more); add or subtract month-aware durations; compute the difference between two dates in every unit plus a human-readable summary; and convert between unix timestamps and ISO. Every endpoint accepts input via the query string or the request body. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for scheduling, billing periods, reminders, analytics and any date arithmetic. (For the current time in a specific timezone, see the oanor Time API.)

api.oanor.com/datetime-api

A fast, fully-local string similarity and fuzzy-matching toolkit: edit distances (Levenshtein, Damerau-Levenshtein, Hamming), normalized 0-1 similarity scores (Levenshtein ratio, Jaro, Jaro-Winkler, Dice and Jaccard), Soundex phonetic codes, and best-match ranking of a query against a candidate list. Every endpoint accepts input via the query string or the request body. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for record matching and deduplication, search and autocomplete, spell-checking, data cleaning and entity resolution.

api.oanor.com/similarity-api

A fast, fully-local Markdown toolkit: render GitHub-flavored Markdown to HTML that is sanitized by default (scripts, style/iframe tags, inline event handlers and javascript: URLs are stripped), strip Markdown down to clean plain text, and extract a heading table of contents with levels, text and URL slugs. Every endpoint accepts input via the query string or the request body (up to 1 MB). Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for CMS and documentation tools, comment systems, static-site pipelines and content rendering.

api.oanor.com/markdown-api

A fast, fully-local JSON and CSV toolkit: validate JSON (with a clear error message, type and size), pretty-print and format it (with optional deep key-sorting), minify it (reporting bytes saved), and convert between CSV and JSON — RFC-4180 CSV parsing with automatic value typing, and JSON arrays to CSV. Every endpoint accepts input via the query string or the request body (up to 1 MB). Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for data pipelines, ETL, webhooks, config tooling and developer utilities.

api.oanor.com/json-api

A fast, fully-local User-Agent parser: detect the browser (name and version), rendering engine, operating system (name and a friendly version), device type (desktop, mobile, tablet, TV, wearable or bot), a mobile flag, and bot/crawler identity (Googlebot, Bingbot, social-preview bots, GPTBot/ClaudeBot, curl and more). Bot detection is included on every plan. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for analytics, ad-tech, fraud and bot filtering, personalization and access logs.

api.oanor.com/useragent-api

A fast, fully-local payment-card toolkit: validate card numbers with the Luhn (mod-10) checksum, detect the brand by IIN/prefix (Visa, Mastercard including the 2-series, American Express, Discover, Diners, JCB, UnionPay, Maestro), format and mask numbers with brand-correct grouping, list supported brands with their valid lengths and CVV length, and generate synthetic Luhn-valid TEST card numbers for QA. Pure server-side compute, no third-party upstream, and inputs are never logged. It is algorithmic only (no real issuer/bank BIN-database lookup). Ideal for checkout forms, payment flows, fraud pre-checks and test fixtures.

api.oanor.com/creditcard-api

A fast, fully-local password toolkit: generate cryptographically-secure random passwords (configurable length, character classes and exclude-similar), estimate password strength (entropy bits, a 0-4 score, character-class breakdown, common-password detection, an offline crack-time estimate and actionable feedback), and create memorable diceware-style passphrases. Built on Node crypto, no third-party upstream, and inputs are never logged — so responses are instant, private and always available. Ideal for signup and account flows, admin tools, password managers and security features.

api.oanor.com/password-api

A fast, fully-local great-circle geospatial toolkit: compute the haversine distance between two coordinates (in km, m, miles or nautical miles), the initial and final compass bearing, the geographic midpoint, the destination point reached from an origin on a bearing at a given distance, and a bounding box around a center for a radius. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for logistics, delivery and fleet apps, store locators, real-estate search, travel and mapping tools.

api.oanor.com/geo-api

A fast, fully-local text-utilities toolkit: convert between 10 case styles (upper, lower, title, sentence, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case), generate URL-friendly slugs, compute text statistics (word, character, sentence, line and paragraph counts, average word length and reading time), and produce lorem-ipsum placeholder text by words, sentences or paragraphs. Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for CMS, editors, developer tools, forms and content pipelines.

api.oanor.com/text-api

A fast, fully-local encoding toolkit: encode and decode text between base64, base64url, base32 (RFC 4648), hex, URL percent-encoding, HTML entities, binary and ASCII85 — plus JWT inspection (decode header and payload without verifying the signature). Pure server-side compute, no third-party upstream, so responses are instant and always available. Ideal for developer tools, webhooks, data pipelines, debugging and integrations.

api.oanor.com/encoding-api

Fast, deterministic unit conversion across 10 categories — length, mass, temperature, area, volume, speed, time, digital storage, pressure and energy. Convert any value between compatible units and list the full unit catalog per category. Fully local compute (no third-party upstream), so responses are instant and always available. Ideal for calculators, e-commerce, logistics, engineering tools, dashboards and chatbots.

api.oanor.com/unit-api

Compute cryptographic hashes (MD5, SHA-1, SHA-256/384/512, SHA-3, RIPEMD-160) in hex or base64, generate HMAC signatures for webhook and message authentication, and mint v4 UUIDs. All server-side and deterministic. Handy for integrity checks, signing, cache keys, deduplication and id generation.

api.oanor.com/hash-api

Generate realistic fake data — users, postal addresses, companies and products — for testing, prototyping, demos and database seeding. Localizable to many languages and regions for names, addresses and phone numbers. Server-side and deterministic to call, ideal for CI fixtures and frontend mock states.

api.oanor.com/mockdata-api

Generate barcodes as PNG images — EAN-13, EAN-8, UPC-A/E, Code 128, Code 39, ITF-14, ISBN and 2D codes (QR, Data Matrix, PDF417, Aztec) — returned as base64 or a raw image, with adjustable size and human-readable text. Fully server-side. Perfect for retail, inventory, shipping labels, ticketing and asset tracking.

api.oanor.com/barcode-api

Search Stack Overflow and the Stack Exchange network — questions by relevance with scores, answer counts and tags, full question details, and user profiles with reputation, badges and location. Ideal for developer tools, tech-trend monitoring, Q&A aggregation and reputation lookups.

api.oanor.com/stackexchange-api

Find words by meaning, sound and spelling — similar-meaning words (thesaurus), rhymes, autocomplete suggestions and wildcard spelling matches. Backed by Datamuse. Ideal for writing assistants, autocomplete, crosswords, word games, poetry tools and NLP preprocessing.

api.oanor.com/words-api