Free developer tools online

Preview STL and OBJ meshes locally. Tentaco 3D & CAD Light: review input and get an instant result — free, no sign-up.

Preview A-Frame XR scenes locally in Reality Lab.

Falling sand and elemental reactions in the browser.

List glTF animation clips and scrub playback locally.

Particle life simulation — local-first Reality Lab experiment.

Workflow presets and auto-pipelines. Tentaco Automation Studio: review input and get an instant result — free, no sign-up.

Planned VRM + MediaPipe body puppet (honest stub).

Run axe-core accessibility checks on your HTML Studio preview.

Encode text to Base32. Tentaco Base32 Encoder: review input and get an instant result — free, no sign-up.

Encode text to Base64 or decode Base64 back to plain text. Tentaco Base64 Encoder / Decoder: review input and get an instant result — free, no sign-up.

Encode or decode files as Base64 locally. Tentaco Base64 File Encoder: review input and get an instant result — free, no sign-up.

URL-safe Base64 encoding. Tentaco Base64 URL Encode: review input and get an instant result — free, no sign-up.

Chip-tune style BeepBox reactor experiment in Reality Lab.

Convert between numeric and symbolic Unix file permissions. Tentaco chmod Calculator: review input and get an instant result — free, no sign-up.

Preview axis-aligned bounding boxes (AABB) over a glTF/GLB mesh in your browser — inspect collision bounds without installing a 3D desktop suite.

Parse Set-Cookie and Cookie header strings. Tentaco Cookie Inspector: review input and get an instant result — free, no sign-up.

Test cross-origin requests via proxy. Tentaco CORS Tester: review input and get an instant result — free, no sign-up.

Validate card number checksum (Luhn). Tentaco Credit Card Validator: review input and get an instant result — free, no sign-up.

Build cron expressions from simple fields. Tentaco Cron Builder: review input and get an instant result — free, no sign-up.

Translate a 5-field cron expression into plain language. Tentaco Cron Expression Explainer: review input and get an instant result — free, no sign-up.

Build cron schedules visually. Tentaco Cron Expression Builder: review input and get an instant result — free, no sign-up.

Parse a cron expression into a human-readable schedule. Tentaco Cron Parser: review input and get an instant result — free, no sign-up.

Check if a cron expression has 5–6 fields. Tentaco Cron Validator: review input and get an instant result — free, no sign-up.

Decode CSP directives for readability. Tentaco CSP Decoder: review input and get an instant result — free, no sign-up.

Build Content-Security-Policy headers. Tentaco CSP Generator: review input and get an instant result — free, no sign-up.

Minify CSS by removing comments and whitespace. Tentaco CSS Minifier: review input and get an instant result — free, no sign-up.

Turn CSV data into structured JSON (and back). Tentaco CSV to JSON Converter: review input and get an instant result — free, no sign-up.

CSV, TSV, query strings and table tools in one workspace. Tentaco Data Studio: review input and get an instant result — free, no sign-up.

ESP Web Serial notes and device forge helpers.

Haversine distance matrix between multiple coordinates.

Resolve A, AAAA, MX, TXT and CNAME records. Tentaco DNS Lookup: review input and get an instant result — free, no sign-up.

Basic Dockerfile best-practice hints. Tentaco Dockerfile Linter: review input and get an instant result — free, no sign-up.

Compare two Office documents and highlight changes.

Preview Word documents locally in the browser.

Extract and inspect tables from DOCX files.

Validate EAN-8 and EAN-13 barcodes. Tentaco EAN Validator: review input and get an instant result — free, no sign-up.

Diff two .env files. Tentaco Env File Diff: review input and get an instant result — free, no sign-up.

Parse .env files into JSON or export as key=value lines. Tentaco .env File Parser: review input and get an instant result — free, no sign-up.

Convert Unix ms timestamps to local time. Tentaco Epoch Milliseconds: review input and get an instant result — free, no sign-up.

Escape special characters for HTML. Tentaco Escape HTML: review input and get an instant result — free, no sign-up.

Pull valid JSON objects from mixed text. Tentaco Extract JSON: review input and get an instant result — free, no sign-up.

MediaPipe eye-control rebuild path (no GPLv3 WebGazer).

Inspect, compare and transform any file locally in your browser. Tentaco File Studio: review input and get an instant result — free, no sign-up.

Experimental fluid / reaction-diffusion playground.

PLY splat stub with link to SuperSplat editor.

Measure polygon areas and compute Turf intersections.

Find the geographic midpoint of several places — average lat/lng for meetups, trips and map planning in your browser.

Compute min/max coordinates from GeoJSON. Tentaco GeoJSON Bounding Box: review input and get an instant result — free, no sign-up.

Draw points, lines and polygons and export GeoJSON.

Format and validate GeoJSON with feature stats. Tentaco GeoJSON Formatter: review input and get an instant result — free, no sign-up.

Compact GeoJSON to a single line. Tentaco GeoJSON Minify: review input and get an instant result — free, no sign-up.

Interactive MapLibre preview for GeoJSON features.

Inspect GeoJSON type, feature and geometry counts. Tentaco GeoJSON Validator: review input and get an instant result — free, no sign-up.

Planned MediaPipe gesture control path (honest stub).

Generate a .gitignore for common stacks. Tentaco .gitignore Generator: review input and get an instant result — free, no sign-up.

Preview GLB and glTF models locally with Three.js.

Break down buffer vs texture footprint in a GLB/glTF.

Estimate authoring units from world-space bounding boxes.

Preview GPX tracks and KML placemarks on a map.

Generate Uber H3 hexagon cells for a location or area.

Inspect HTTP Archive (HAR) capture files. Tentaco HAR Viewer: review input and get an instant result — free, no sign-up.

Guess hash algorithm from length and prefix (MD5, SHA-256, bcrypt, …). Tentaco Hash Identifier: review input and get an instant result — free, no sign-up.

Decode hex back to text. Tentaco Hex Decoder: review input and get an instant result — free, no sign-up.

Convert text to hexadecimal bytes. Tentaco Hex Encoder: review input and get an instant result — free, no sign-up.

Escape or unescape HTML entities like & and <. Tentaco HTML Entity Encoder / Decoder: review input and get an instant result — free, no sign-up.

Encode and decode HTML entities (&, <, …). Tentaco HTML Entity Encoder: review input and get an instant result — free, no sign-up.

Minify HTML in your browser. Remove whitespace and comments — copy compact markup instantly.

Browser HTML/CSS/JS editor with live sandboxed preview, templates and export. Tentaco HTML Studio: review input and get an instant result — free, no sign-up.

Strip HTML tags and get readable plain text. Tentaco HTML to Plain Text: review input and get an instant result — free, no sign-up.

Compare two HTTP header blocks. Tentaco HTTP Header Diff: review input and get an instant result — free, no sign-up.

Validate IBAN checksum and country format. Tentaco IBAN Validator: review input and get an instant result — free, no sign-up.

Compress and expand IPv6 addresses. Tentaco IPv6 Compress: review input and get an instant result — free, no sign-up.

Remove whitespace and comments from JavaScript code. Tentaco JavaScript Minifier: review input and get an instant result — free, no sign-up.

Parametric keychain or box — export ASCII STL.

Escape or unescape strings for use inside JSON. Tentaco JSON String Escaper: review input and get an instant result — free, no sign-up.

Flatten nested JSON into dot-notation keys. Tentaco JSON Flatten: review input and get an instant result — free, no sign-up.

Beautify, minify and validate JSON in your browser. Syntax errors with line hints — copy or download instantly.

Minify JSON to one line. Tentaco JSON Minify: review input and get an instant result — free, no sign-up.

Resolve RFC 6901 JSON Pointer paths against JSON. Tentaco JSON Pointer: review input and get an instant result — free, no sign-up.

Beautify JSON with indentation. Tentaco JSON Pretty Print: review input and get an instant result — free, no sign-up.

Infer JSON Schema from sample JSON. Tentaco JSON Schema Generator: review input and get an instant result — free, no sign-up.

Validate JSON against a draft-07 schema. Tentaco JSON Schema Validator: review input and get an instant result — free, no sign-up.

Recursively sort JSON object keys. Tentaco JSON Sort Keys: review input and get an instant result — free, no sign-up.

Generate TypeScript interfaces from a JSON sample. Tentaco JSON to TypeScript: review input and get an instant result — free, no sign-up.

Convert JSON objects to XML markup. Tentaco JSON to XML: review input and get an instant result — free, no sign-up.

Format, validate and convert JSON, XML, SQL, HTML, CSS, JS and more — one developer workspace.

Compare two JSON or XML files side by side. Tentaco JSON / XML File Diff: review input and get an instant result — free, no sign-up.

Convert between JSON and YAML in both directions. Tentaco JSON ↔ YAML Converter: review input and get an instant result — free, no sign-up.

Build and sign JWT tokens locally. Tentaco JWT Builder: review input and get an instant result — free, no sign-up.

Decode and inspect JSON Web Tokens in your browser. Header, payload and signature — no upload.

Read exp claim from a JWT. Tentaco JWT Expiry Check: review input and get an instant result — free, no sign-up.

Decode JWT header, payload and expiry details. Tentaco JWT Inspector: review input and get an instant result — free, no sign-up.

Analyze a place with H3 cell, sun position and shadow length.

Run Luhn algorithm on numeric strings. Tentaco Luhn Check: review input and get an instant result — free, no sign-up.

GeoJSON, coordinates and distance tools. Tentaco Map & Geo Studio: review input and get an instant result — free, no sign-up.

Convert Markdown to clean HTML markup. Tentaco Markdown to HTML: review input and get an instant result — free, no sign-up.

Inspect PBR materials and texture slots in a glTF.

Triangle count and bounding size for STL/OBJ. Tentaco Mesh Statistics: review input and get an instant result — free, no sign-up.

Compile MJML to responsive email HTML locally.

Side-by-side A/B preview of two GLB/glTF files.

Prune, weld and resample glTF with glTF Transform.

Assemble email-safe HTML newsletter layouts locally.

Astronomy view with SunCalc and an illustrative star field.

Convert numbers between binary, octal, decimal and hexadecimal. Tentaco Number Base Converter: review input and get an instant result — free, no sign-up.

Inspect DOCX/XLSX/PPTX metadata, parts and package flags.

Compare two OpenAPI YAML/JSON specs. Tentaco OpenAPI Diff: review input and get an instant result — free, no sign-up.

Generate sample JSON from OpenAPI schemas. Tentaco OpenAPI Mock Generator: review input and get an instant result — free, no sign-up.

Browse and format OpenAPI/Swagger specs. Tentaco OpenAPI Viewer: review input and get an instant result — free, no sign-up.

Play with a fountain-style particle universe in Reality Lab — tweak emitters and motion live in your browser.

Limited GLB product-shot path tracer in Reality Lab.

Inspect PEM certificates and keys. Tentaco PEM Parser: review input and get an instant result — free, no sign-up.

Normalize and format international phone numbers. Tentaco Phone Number Format: review input and get an instant result — free, no sign-up.

Drop a ball onto a glTF mesh with Rapier gravity.

Point-cloud metadata stub (Potree not embedded).

In-browser Postgres (PGlite) for local SQL experiments.

Build a simple PowerPoint presentation locally.

Convert .properties / env lines to JSON. Tentaco Properties to JSON: review input and get an instant result — free, no sign-up.

Encode and decode internationalized domain names (IDN). Tentaco Punycode Encoder: review input and get an instant result — free, no sign-up.

Run Python in the browser with Pyodide — no server.

Explore Quirk-style quantum circuits in an iframe sandbox.

Convert URL query strings to JSON and back. Tentaco Query String ↔ JSON: review input and get an instant result — free, no sign-up.

Pick a random destination inside a radius around a point.

Local-first experiments — particle life, orbits, quantum circuits and kinetic art.

Escape literal text for safe use in regular expressions. Tentaco Regex Escape: review input and get an instant result — free, no sign-up.

Test regular expressions with live highlighting, capture groups and replace preview — in your browser.

Compare two homes against POIs for a move.

v86 emulator shell — bring your own ISO (emulator deferred).

Fetch and validate robots.txt for a site. Tentaco robots.txt Tester: review input and get an instant result — free, no sign-up.

Visualize TLE satellite orbits on an Earth globe.

Bump patch, minor or major version. Tentaco Semver Bump: review input and get an instant result — free, no sign-up.

Compare two semantic version strings. Tentaco SemVer Comparator: review input and get an instant result — free, no sign-up.

Compare two semantic versions. Tentaco Semver Diff: review input and get an instant result — free, no sign-up.

Validate sitemap.xml structure and URLs. Tentaco Sitemap Validator: review input and get an instant result — free, no sign-up.

Interactive spreadsheet with formulas, formatting, sheets and local autosave. Tentaco Spreadsheet Studio: review input and get an instant result — free, no sign-up.

Format SQL queries with keyword casing and line breaks. Tentaco SQL Formatter: review input and get an instant result — free, no sign-up.

Generate INSERT statements from JSON rows. Tentaco SQL INSERT Generator: review input and get an instant result — free, no sign-up.

Run SQL against CSV/Parquet locally with DuckDB WASM.

Uppercase SQL keywords for readability. Tentaco SQL Keyword Uppercase: review input and get an instant result — free, no sign-up.

Inspect TLS certificate for a hostname. Tentaco SSL Certificate Viewer: review input and get an instant result — free, no sign-up.

Count UTF-8 and UTF-16 byte length of a string. Tentaco String Byte Length: review input and get an instant result — free, no sign-up.

Remove UTF-8 byte order mark. Tentaco Strip BOM: review input and get an instant result — free, no sign-up.

Compute sun azimuth, altitude and shadow rays with SunCalc.

Play Flash SWF files locally with Ruffle WASM.

xterm.js terminal with a tiny fake learning shell.

Check glTF texture resolution, MIME type and usage.

Convert between Unix timestamps and human-readable dates. Tentaco Unix Timestamp Converter: review input and get an instant result — free, no sign-up.

Convert TOML config to JSON. Tentaco TOML to JSON: review input and get an instant result — free, no sign-up.

Inspect .torrent and magnet metadata only — no downloads.

Convert between tab-separated and comma-separated values. Tentaco TSV ↔ CSV Converter: review input and get an instant result — free, no sign-up.

Decode HTML entities to plain text. Tentaco Unescape HTML: review input and get an instant result — free, no sign-up.

Look up code point, UTF-8 bytes and name for any character. Tentaco Unicode Character Info: review input and get an instant result — free, no sign-up.

Unix and ISO timestamps for now. Tentaco Current Timestamp: review input and get an instant result — free, no sign-up.

URL-encode each line. Tentaco Batch URL Encode: review input and get an instant result — free, no sign-up.

Percent-encode or decode URLs and query string components. Tentaco URL Encoder / Decoder: review input and get an instant result — free, no sign-up.

Break a URL into protocol, host, path, query and hash. Tentaco URL Parser: review input and get an instant result — free, no sign-up.

Inspect UUID version and variant. Tentaco UUID Inspector: review input and get an instant result — free, no sign-up.

Build multi-step file transform pipelines visually.

Experimental local LLM swarm notes (opt-in heavy models).

Convert POINT WKT to GeoJSON. Tentaco WKT Converter: review input and get an instant result — free, no sign-up.

Beautify and indent XML, or minify it to one line. Tentaco XML Formatter: review input and get an instant result — free, no sign-up.

Convert XML documents to JSON. Tentaco XML to JSON: review input and get an instant result — free, no sign-up.

Check XML well-formedness locally. Tentaco XML Validator: review input and get an instant result — free, no sign-up.

Validate YAML syntax with clear errors. Tentaco YAML Validator: review input and get an instant result — free, no sign-up.

Draw chemical structures with Ketcher (Indigo WASM) locally.

Multi-cell Pyodide notebook with markdown and code — saves locally.

Educational voltage divider and LED series resistor calculator (no CircuitJS).

Join a Trystero BitTorrent room for peer chat — no API keys.

Browser spreadsheet editor with formulas, sheets and local autosave. Tentaco Online Spreadsheet: review input and get an instant result — free, no sign-up.

Generate sample JSON from OpenAPI schemas. Tentaco Openapi Mock: review input and get an instant result — free, no sign-up.

Inspect JWT header and payload in Security Studio. Tentaco Jwt Debugger: review input and get an instant result — free, no sign-up.

Compare two JSON or XML files side by side. Tentaco Json Xml Diff: review input and get an instant result — free, no sign-up.

Validate JSON-LD structured data against common schema.org patterns before deploy. Tentaco Json Ld Validator: review input and get an instant result — free, no sign-up.

Format, minify, convert and inspect JSON in your browser — CSV, YAML, XML, JWT and GraphQL helpers with no upload.