#converter

Live foreign-exchange conversion across 160+ world currencies — the plain, developer-friendly converter. Get the latest rates for any base currency, convert an amount between any two currencies, read the rate (and inverse) for a single pair, or list every supported currency. Rates are read live from an open exchange-rate source that aggregates a broad set of feeds and covers far more currencies than ECB-only data — including emerging-market and exotic currencies such as the Nigerian naira, Indian rupee or Vietnamese dong. This is the everyday convert / latest-rates utility a checkout, invoice, pricing page or travel app needs — distinct from the FX analytics APIs in the catalogue (historical date ranges, pip and position-size calculators, triangular-arbitrage path maths, currency indices), which compute on rates rather than simply converting them.

api.oanor.com/currencyconverter-api

Live crypto price and currency conversion, served from the public CoinGecko feed with no key and nothing cached. This is a conversion utility, distinct from market-overview, arbitrage and coin-profile tools: it tells you what a coin is worth right now and converts an amount between coins and fiats. The price endpoint returns the live price of one or more coins in one or more currencies at once, each with its market cap, 24-hour volume and 24-hour change — pull Bitcoin and Ethereum in USD, EUR and BTC in a single call. The convert endpoint converts an amount of a coin into a fiat currency or into another coin: two Bitcoin to euros, or one and a half Bitcoin to Ether, with the rate and the result. Coin-to-coin conversions are crossed through USD automatically. The supported endpoint lists every currency you can quote or convert into — dozens of fiats plus the major coins. Everything is read live from CoinGecko on each request, nothing stored beyond a short protective cache. Ideal for wallets, checkout and payment flows, portfolio trackers, price tickers and dashboards. Coin ids are lowercase CoinGecko ids (bitcoin, ethereum, solana). Live, no key. 3 endpoints. For prices by on-chain contract address use a token-price API.

api.oanor.com/cryptoconvert-api

Roman numeral conversion as an API, computed locally and deterministically. The encode endpoint turns an integer from 1 to 3999 into its Roman numeral using standard subtractive notation, so 1994 becomes MCMXCIV and 2024 becomes MMXXIV. The decode endpoint turns a Roman numeral back into an integer with strict validation — it rejects malformed forms such as IIII or VV and also returns the canonical way to write the same value, accepting any letter case. The arithmetic endpoint adds, subtracts or multiplies two values given as either integers or Roman numerals and returns the result as a Roman numeral and as an integer, provided the result stays within the classic 1–3999 range. The standard subtractive pairs are IV, IX, XL, XC, CD and CM. Everything is computed locally and deterministically, so it is instant and private. Ideal for typesetting, publishing, education, clock-face, game and document-processing app developers, numbering and chapter tools, and history teaching. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is Roman numeral conversion; for binary, octal and hexadecimal number-base conversion use a base-conversion API.

api.oanor.com/roman-api

Convert HTML into clean GitHub-Flavored Markdown. Pass an HTML string, or a live page URL to fetch and convert, and get back tidy Markdown — headings, bold/italic, links, images, lists, blockquotes, code blocks, plus GFM tables, strikethrough and task lists. Script, style and head elements are stripped automatically. Tune the output: ATX or setext headings, the bullet marker, fenced or indented code blocks, inline or referenced links, and the emphasis/strong delimiters; toggle GFM on or off. The inverse of a Markdown-to-HTML renderer. Pure local conversion (the optional URL fetch aside) — no key, no third-party service, instant. Live. 3 endpoints. Built for content migration, web clipping and "save as Markdown", scraping cleanup, CMS import and documentation pipelines.

api.oanor.com/htmltomarkdown-api

Convert and validate TOML — the config format behind Cargo.toml, pyproject.toml, Netlify and many tools. Turn TOML into JSON, turn JSON back into clean spec-compliant TOML 1.0, and validate any TOML with a precise error message (line and column) when it is malformed. Tables, arrays of tables, inline tables, typed values and datetimes are all handled. Input via the query string or the request body (up to 4 MB). Pure local processing — no key, no third-party service, instant. Live. 4 endpoints. Completes the oanor config-format family alongside the JSON, YAML, XML and CSV APIs — built for build tooling, config editors, CI and data pipelines.

api.oanor.com/toml-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 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

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