26 catalogued formats
Web Formats
Web formats are interpreted by browsers and build tools rather than opened as standalone documents. HTML describes structure, CSS describes presentation, JavaScript adds behavior, and assets such as images, fonts, and WebAssembly modules are fetched separately. Compatibility depends on the browser and the build pipeline.
Why this format suite matters
- Serving the wrong MIME type can make a valid file fail in the browser.
- Modern JavaScript and CSS may need transpilation or fallbacks.
- Asset formats have different support across browsers and devices.
Common formats in this suite
A sample of the catalog. Not every extension has a live converter.
| Format | Extension | MIME | Notes |
|---|---|---|---|
| ASCX | .ascx | application/octet-stream | ASCX web format |
| ASHX | .ashx | application/octet-stream | ASHX web format |
| ASMX | .asmx | application/octet-stream | ASMX web format |
| ATOM | .atom | application/octet-stream | ATOM web format |
| AXD | .axd | application/octet-stream | AXD web format |
| CJS | .cjs | application/octet-stream | CJS web format |
| CSHTML | .cshtml | application/octet-stream | CSHTML web format |
| HANDLEBARS | .handlebars | application/octet-stream | HANDLEBARS web format |
| HBS | .hbs | application/octet-stream | HBS web format |
| JSONLD | .jsonld | application/octet-stream | JSONLD web format |
| JSPX | .jspx | application/octet-stream | JSPX web format |
| JSX | .jsx | application/octet-stream | JSX web format |
| LIQUID | .liquid | application/octet-stream | LIQUID web format |
| MANIFEST | .manifest | application/octet-stream | MANIFEST web format |
| MJS | .mjs | application/octet-stream | MJS web format |
| MUSTACHE | .mustache | application/octet-stream | MUSTACHE web format |
| NJK | .njk | application/octet-stream | NJK web format |
| NUNJUCKS | .nunjucks | application/octet-stream | NUNJUCKS web format |
| RSS | .rss | application/octet-stream | RSS web format |
| TWIG | .twig | application/octet-stream | TWIG web format |
| VASH | .vash | application/octet-stream | VASH web format |
| VBHTML | .vbhtml | application/octet-stream | VBHTML web format |
| WEBMANIFEST | .webmanifest | application/octet-stream | WEBMANIFEST web format |
| WXL | .wxl | application/octet-stream | WXL web format |
Showing 24 of 26 catalogued formats. Use the converter directory for supported tools.
Common workflows
Static sites
Use HTML, CSS, and assets with a clear folder structure.
Web applications
Bundle scripts and test the output in the browsers you support.
Performance
Choose modern image and font formats with fallbacks for older clients.
Before you convert
Start with the application that must open the result. Use HTML, CSS, and assets with a clear folder structure. Keep the original file until the output has been opened and checked. A format name alone does not guarantee compatibility, especially for web formats data that may include references, layers, or platform-specific metadata.
- Confirm the source file opens correctly in its original application.
- Identify the exact format and version the destination accepts.
- Keep the source until the converted file has been reviewed.
Frequently asked questions
- Can I convert HTML to a website?
- HTML is the site source. You still need CSS, assets, and a server or static host.
- Why does a JavaScript file fail in an older browser?
- It may use syntax or APIs that the browser does not support. Transpile and polyfill where needed.
- What is WebAssembly?
- A compact binary format for running compiled code in browsers at near-native speed.
- Which image format should a website use?
- Use WebP or AVIF with fallbacks, and keep PNG for transparency or sharp graphics when needed.
- What should I check before converting a web formats file?
- Confirm that the source opens in its original application, identify the format the destination requires, and keep an untouched copy. Test one representative file before processing a batch, especially when metadata, links, geometry, or layout matters.