API marketplace

Summarize text and pull out its keywords — no AI key, no external model. The summarize endpoint is extractive: it scores every sentence by word frequency and position and returns the most representative ones (ask for a fixed number of sentences or a fraction of the original), keeping the author's exact wording and order. The keywords endpoint ranks the most salient terms with their counts and a relative score, filtering out stopwords. Because it is deterministic and runs locally, the same text always gives the same result, instantly and privately. Perfect for article previews and TL;DRs, search snippets, tagging and content triage, and feeding shorter context to downstream tools. Pure local computation — no third-party service; send long text via POST. Live, nothing stored. 3 endpoints. Distinct from sentiment/NLP analysis, stopword lists and Unicode text segmentation.

Uptime

100.0%

Latency

81ms

Subs

4,691

Spreadsheet cell-reference maths for Excel, Google Sheets, LibreOffice and CSV tooling. Parse an A1 reference (AA10) into its column letter, 1-based column number, row and R1C1 form; build an A1 (and R1C1) reference from a row and a column given either as a letter or a number; and convert a column letter to its number and back (A→1, Z→26, AA→27, ZZ→702). Absolute markers ($A$1) are accepted. Perfect for code that generates spreadsheets, maps data to cells, builds formulas, or imports and exports ranges. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 4 endpoints. Distinct from CSV parsing and from generic number-base conversion.

Uptime

100.0%

Latency

76ms

Subs

4,863

Convert between INI configuration files and JSON, in both directions. The parse endpoint reads INI text — sections ([section]), nested sections ([database.replica]), key=value pairs, comments and repeated keys (arrays) — into a clean JSON object; the stringify endpoint turns a JSON object back into a properly formatted INI file. INI is the config format used by Git (.gitconfig), PHP (php.ini), systemd units, desktop entries, tox/setup.cfg, many CLI tools and Windows software. Perfect for editing config programmatically, migrating settings between formats, and reading config in environments that only speak JSON. Pure local computation — no key, no third-party service, instant; send large files via POST. Live, nothing stored. 3 endpoints. Complements the YAML, TOML, CSV and XML converters and is distinct from each.

Uptime

100.0%

Latency

76ms

Subs

3,692

Aspect-ratio and resize maths on plain dimensions — no image upload needed. The ratio endpoint reduces a width×height to its simplest integer ratio (1920×1080 → 16:9), its decimal value and a common name. The resize endpoint scales a dimension while preserving the ratio: give a new width or a new height and get the other side. The fit endpoint fits a source size into a target box using contain (letterbox) or cover (crop), returning the resulting size, the scale factor and the centering offset. Perfect for responsive layouts and CSS aspect-ratio, video and thumbnail framing, image-grid planning and print sizing. Pure local computation — it works on numbers only and never touches image files. Live, nothing stored. 4 endpoints. Distinct from image processing/resizing (which operates on actual files) and from geometry of shapes.

Uptime

100.0%

Latency

72ms

Subs

4,198

Convert SMPTE timecode for video, film and broadcast. Turn a timecode (HH:MM:SS:FF) into an absolute frame number or into real-time seconds, and turn a frame count back into a timecode — at 23.976, 24, 25, 29.97, 30, 50, 59.94 or 60 fps. Crucially it handles drop-frame correctly: at 29.97 and 59.94 fps it drops the right frame numbers each minute (notated with a semicolon, 01:00:00;00) so an hour of timecode lines up with an hour of real time, and it computes real seconds with the exact fractional rate (30000/1001). Perfect for NLE and editing tools, subtitle and caption timing, playout and broadcast automation, and media asset management. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 4 endpoints. Distinct from date/time, duration and relative-time tools.

Uptime

100.0%

Latency

79ms

Subs

4,486

Humanize, parse and convert byte sizes. Turn a raw byte count into a human-readable string (1610612736 → 1.5 GiB or 1.61 GB), parse a human size back into bytes ("1.5 GiB", "2GB", "500 kB" → the exact integer), and convert an amount between any two units. Handles both the IEC binary units (KiB, MiB, GiB, TiB — powers of 1024) and the SI decimal units (kB, MB, GB, TB — powers of 1000), with configurable decimal places and case-insensitive unit names. Perfect for dashboards and admin UIs, file-upload limits, storage and bandwidth reporting, logs and CLI output. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 4 endpoints. Distinct from file-type detection and from number/unit measurement conversion.

Uptime

100.0%

Latency

77ms

Subs

3,380

Read and write the front-matter metadata block at the top of Markdown and content files — the --- ... --- header used by Jekyll, Hugo, Astro, Eleventy, Gatsby, Next.js MDX and Obsidian. The parse endpoint splits a document into its structured front-matter data (title, tags, date, draft flags and anything else, as proper JSON), the body content and an optional excerpt, and tells you whether front matter was present. The stringify endpoint does the reverse: give it a JSON object of fields and a body, and it returns a clean Markdown file with a YAML front-matter block. Front matter is read as YAML (which also accepts JSON). Perfect for static-site build steps, headless-CMS imports, content migrations and validating posts. Pure local computation — no key, no third-party service, instant; send large documents via POST. Live, nothing stored. 3 endpoints. Distinct from Markdown rendering / table-of-contents extraction and from YAML/TOML format conversion.

Uptime

100.0%

Latency

78ms

Subs

4,783

Convert geometry between WKT (Well-Known Text) and GeoJSON, in both directions. WKT is the textual geometry format used by PostGIS, Spatialite, GEOS, JTS, Shapely and the OGC Simple Features standard (POINT (30 10), LINESTRING (...), POLYGON ((...))); GeoJSON is what web maps and JavaScript expect. The to-geojson endpoint turns a WKT string into a GeoJSON geometry, and to-wkt does the reverse from a GeoJSON geometry or Feature. Supports Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon and GeometryCollection. Perfect for bridging a spatial database and a front-end map, importing and exporting geometry, and data-migration scripts. Pure local computation — no key, no third-party service, instant; send large geometries via POST. Live, nothing stored. 3 endpoints. Distinct from coordinate-format conversion, EPSG/CRS lookups, slippy map tiles and GeoJSON geospatial metrics.

Uptime

100.0%

Latency

83ms

Subs

3,663

Clean up and parse personal names. The case endpoint applies proper name-casing that ordinary title-casing gets wrong — McDonald, MacLeod, O'Brien, D'Angelo, hyphenated double-barrelled names, lower-case particles (van, von, de, la, der) and Roman-numeral suffixes (II, III, IV). The parse endpoint splits a full name into salutation, first, middle and last name and suffix, and also returns a properly-cased version of each part. Perfect for tidying user sign-ups, CRM and mailing lists, deduplicating contacts, formatting names on documents and normalising imported data. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. Parsing is tuned for Western (given-name-first) order. Distinct from baby-name popularity data and locale display-name lookups.

Uptime

100.0%

Latency

81ms

Subs

4,104

Shrink and clean SVG files automatically with SVGO, the industry-standard SVG optimiser. The optimize endpoint strips comments, metadata, editor cruft and redundant attributes, collapses and merges paths, and returns minified markup together with the original and optimised byte sizes and the percentage saved — typically 30-60% smaller. The data-uri endpoint goes one step further and returns a ready-to-paste CSS data URI (URL-encoded or base64) plus the matching background-image rule, so you can inline icons without an extra HTTP request. Perfect for build pipelines, icon systems, design tooling, email and embedding SVGs in CSS. Pure local processing — no key, no third-party service, instant; send markup via POST for large files (up to 2 MB). Live, nothing stored. 3 endpoints. Distinct from raster image compression, QR/code generation and JSON/HTML formatting.

Uptime

100.0%

Latency

91ms

Subs

3,888

Measure GeoJSON geometry on the surface of the earth. Compute the true area of a Polygon or MultiPolygon (in square metres, square kilometres, hectares, acres and square miles), find the centroid of any GeoJSON, get the bounding box (west/south/east/north) and its centre, measure the length of a LineString or MultiLineString (in kilometres, metres, miles and nautical miles), and test whether a latitude/longitude point falls inside a polygon. Accepts geometries, Features and FeatureCollections; coordinates follow the GeoJSON [longitude, latitude] order. Perfect for mapping apps, geofencing, territory and catchment analysis, route distances and spatial dashboards. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 6 endpoints. Distinct from abstract shape geometry, coordinate-format conversion, slippy map tiles and administrative-boundary data.

Uptime

100.0%

Latency

76ms

Subs

4,554

Generate colour gradients and colour scales programmatically. Produce an evenly-spaced scale of N colours between two or more stops (interpolated in a perceptually smooth colour space — lab, lch, oklab, oklch — or plain rgb/hsl), get a single interpolated colour at any position between two colours, and build a ready-to-paste CSS gradient string (linear with any angle, or radial) from a list of stops. Colours accept hex (#f00, #ff0000) or CSS names (red, steelblue). Perfect for data-visualisation colour ramps, heatmaps, chart palettes, theme generation and UI backgrounds. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 4 endpoints. Distinct from colour conversion / harmonious palettes (one base colour) and image palette extraction.

Uptime

100.0%

Latency

81ms

Subs

4,550

Run statistics on a list of numbers without a spreadsheet or a stats package. The describe endpoint returns a full summary of a dataset — count, sum, min, max, range, mean, median, mode, the first and third quartiles and interquartile range, population and sample variance and standard deviation, coefficient of variation, geometric and harmonic means, skewness and kurtosis. Get any percentile of a dataset, the Pearson correlation coefficient (and r²) between two equal-length series, and a simple linear regression (slope, intercept, r² and the line equation). Input is a raw array of numbers (JSON or a comma-separated list) — no CSV, no headers. Perfect for analytics, A/B test summaries, sensor and metrics data, dashboards and quick exploratory analysis. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 5 endpoints. Distinct from the mathjs expression engine and from CSV per-column summaries.

Uptime

100.0%

Latency

76ms

Subs

3,025

The maths behind every web map. Convert between latitude/longitude, slippy-map XYZ tile coordinates (the z/x/y scheme used by OpenStreetMap, Google Maps, Mapbox and Leaflet) and Bing/Azure quadkeys, and get the exact Web Mercator (EPSG:3857) bounding box and centre of any tile. Find which tile contains a point at a given zoom, expand a tile to its geographic bounds, translate a quadkey to z/x/y and back, and list a tile's eight neighbours (with correct antimeridian wrap-around and pole clamping). Perfect for tile servers and caches, pre-fetching map tiles, drawing tile grids and debugging map layers. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 5 endpoints. Distinct from coordinate-format conversion (Plus Code/MGRS/UTM), geohash and the encoded-polyline codec.

Uptime

100.0%

Latency

83ms

Subs

3,626

Work with ISO-8601 durations — the PnYnMnDTnHnMnS strings (P3Y6M4DT12H30M5S, PT1H30M) used across calendars, scheduling, video metadata, billing periods and APIs. Parse a duration into its components and a total in seconds and milliseconds; format a number of seconds (or individual year/month/week/day/hour/minute/second fields) back into a canonical ISO-8601 string; humanise any duration into readable text ("1 hour and 30 minutes"); and measure the exact duration between two instants (ISO timestamps or unix epochs) as both an ISO-8601 string and a precise second count. Years and months use documented calendar averages and are clearly flagged as approximate. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 5 endpoints. Distinct from date/time parsing and relative-time ("3 hours ago") formatting.

Uptime

100.0%

Latency

76ms

Subs

4,689

Encode and decode Google/Mapbox encoded polylines — the compact ASCII string used by the Google Maps Directions API, Mapbox, Valhalla, OSRM and GPX-style route geometry to pack a list of coordinates into a few bytes. Decode an encoded string into an array of latitude/longitude points, encode a coordinate list back into a polyline (precision 5, the Google default, or 6 for OSRM/Valhalla overview), and measure a path — point count, total length by the haversine great-circle formula in km and miles, and the bounding box. Perfect for drawing routes on a map, storing tracks compactly, computing trip distance and fitting a map viewport. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 4 endpoints. Distinct from coordinate-format conversion (Plus Code/MGRS/UTM) and geohash.

Uptime

100.0%

Latency

72ms

Subs

4,297

Reduce words to their linguistic root (stem) with the classic Snowball stemming algorithms — running → run, fishing → fish, nationalization → nation — across 24 languages including English, German, French, Spanish, Italian, Portuguese, Dutch, Russian, Arabic, Finnish, Swedish and more. Stem a whole text (every word, returning both the per-word mapping and the fully stemmed text) or a single word. Stemming is the core normalisation step behind search engines, query expansion, text indexing, keyword matching and NLP preprocessing. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 4 endpoints. Distinct from sentiment/NLP analysis and fuzzy string matching.

Uptime

100.0%

Latency

78ms

Subs

3,255

Generate and parse X.509 Certificate Signing Requests (PKCS#10) — the CSRs you submit to a Certificate Authority to obtain a TLS certificate. Generate a CSR from a common name plus optional organisation, country, locality and Subject Alternative Names, and get back the CSR together with a freshly-generated RSA private key (2048/3072/4096). Or parse an existing CSR to read its subject, SANs, key size and whether its signature is valid. Pure local processing — no key, no third-party service. Note: for development and testing; keep production private keys offline. Live, nothing stored. 3 endpoints. Distinct from key-pair generation, certificate decoding and live SSL checks.

Uptime

100.0%

Latency

207ms

Subs

4,339

Decode an X.509 certificate (PEM) into readable details — without a live connection. Paste a certificate and get back its subject and issuer (parsed into fields), the validity window with days-until-expiry and an expired flag, the serial number, SHA-1 and SHA-256 fingerprints, the Subject Alternative Names, the public-key type and size, and the CA / self-signed flags. Pure local parsing with no third-party service. Live, nothing stored. 2 endpoints. Built for certificate inspection, CI/CD expiry checks, PKI debugging and audit tooling. Distinct from a live SSL/TLS endpoint checker — this decodes a certificate you already hold.

Uptime

100.0%

Latency

84ms

Subs

3,550

Generate cryptographic key pairs on demand — RSA (2048/3072/4096), elliptic-curve (P-256, P-384, P-521, secp256k1), Ed25519 and Ed448 — returned as PEM (SPKI public key, PKCS#8 private key) and, optionally, as JWK. Perfect for spinning up JWT/JWS signing keys, TLS and SSH experiments, test fixtures and demos. Pure local generation with Node's crypto (no third-party service). Note: for development, testing and education — generate keys for production systems offline or in an HSM, never trust a remote API with real private keys. Live, nothing stored. 3 endpoints. Distinct from JWT signing, password generation and hashing.

Uptime

100.0%

Latency

81ms

Subs

3,492

Validate cryptocurrency wallet addresses before you send funds or store them. Check an address against a specific coin — Bitcoin (legacy base58check and bech32 SegWit), Ethereum (with EIP-55 checksum), Litecoin, Dogecoin, Bitcoin Cash, XRP, Cardano, Tron, Monero and 100+ others — or let it auto-detect the likely currency across the most popular coins. Optionally restrict to mainnet or testnet. Catches typos, wrong-network mistakes and malformed addresses. Pure local validation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. Built for payment and checkout forms, exchanges and wallets, withdrawal validation and KYT pre-checks. Distinct from blockchain-data and market-price APIs.

Uptime

100.0%

Latency

83ms

Subs

4,738

Work with BIP39 mnemonic seed phrases — the 12-to-24-word recovery phrases used by crypto wallets. Generate a phrase at a chosen strength (128–256 bits) in any of 9 wordlist languages, validate a phrase, convert between a phrase and its raw entropy in both directions, and derive the 512-bit BIP39 seed (with an optional passphrase) used for HD-wallet key derivation. Pure local computation — no key, no third-party service. Note: intended for development, testing and education; generate seeds for real funds offline / client-side, never trust a remote API with production keys. Live, nothing stored. 7 endpoints. Distinct from market-data, password and 2FA tools.

Uptime

100.0%

Latency

75ms

Subs

4,450

Flatten and unflatten JSON. Turn a deeply nested JSON object into a single-level map of dot-notation keys (a.b.c → value, arrays become a.0, a.1), and turn a flat dot-notation map back into the original nested structure. Choose the delimiter (dot, slash, anything), limit the depth, or keep arrays intact. Perfect for environment variables, i18n/translation keys, preparing JSON for CSV or spreadsheet export, analytics event properties, config diffing and form serialisation. Pure local processing — no key, no third-party service, instant. Live. 3 endpoints. Distinct from JSON validation/formatting, JSONPath querying and type inference.

Uptime

100.0%

Latency

91ms

Subs

3,973

Make untrusted HTML safe to display. Send any HTML — a comment, a rich-text submission, a snippet from an email or a scraped page — and get back a clean, XSS-free version: <script> tags, inline event handlers (onclick, onerror), javascript: URLs, <iframe>, <style> and anything not on the allowlist are removed. Override the allowed tags and attributes to fit your needs, or drop links entirely. A strip endpoint returns plain text with all markup removed. Pure local sanitization — no key, no third-party service, instant. Live. 3 endpoints. Built for user-generated content, comment systems, rich-text editors, email rendering and any place untrusted HTML reaches a browser. Distinct from a Markdown renderer or an HTML data extractor.

Uptime

100.0%

Latency

77ms

Subs

4,907