AsciiDoc to HDR Converter
FileFlip converts AsciiDoc to HDR entirely inside your browser, using Pandoc, MuPDF and ImageMagick compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert an AsciiDoc file to HDR?#
- Drop your AsciiDoc file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to HDR and the conversion starts on its own. FileFlip downloads 79.9 MB of WebAssembly the first time and nothing after that, then runs Pandoc, MuPDF and ImageMagick on your own machine.
- Save the HDR file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting AsciiDoc to HDR lose quality?#
Yes, in the sense that text stops being text. Each AsciiDoc page is rendered to pixels and handed to HDR, so the result looks right and can no longer be selected, searched, or reflowed.
Is it safe to convert AsciiDoc files online?#
Yes, because nothing is uploaded. FileFlip converts AsciiDoc files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What AsciiDoc to HDR actually does to the file#
Converting AsciiDoc to HDR runs on Pandoc, MuPDF and ImageMagick, downloads 79.9 MB of WebAssembly the first time and nothing after that, renders each page to pixels, keeps page layout, and drops selectable text and transparency.
| Engine | Pandoc, MuPDF and ImageMagick |
|---|---|
| Conversion path | 3 steps: AsciiDoc → HTML → PNG → HDR |
| Downloaded to your browser | 79.9 MB, once, then cached by your browser |
| Quality | Text becomes pixels |
| You get back | One image per page, zipped when the source has several |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Selectable text | Dropped | The target format has nowhere to put it. |
| Page layout | Kept | Carried through into the converted file. |
| Transparency | Dropped | The target format has nowhere to put it. |
Worth knowing before you start:
- pages render at twice their point size in opaque RGB, roughly 144 DPI, with no transparency
- reflowable input is laid out on a fixed 595x842pt page at 11pt before anything else happens
- the file passes through HTML on the way, so anything HTML cannot express does not survive
What is an AsciiDoc file?#
An ADOC file holds AsciiDoc, a plain-text markup Stuart Rackham designed in 2002 with structural features like admonitions, includes and cross-references built into the syntax rather than bolted on afterward.
Choose AsciiDoc for technical documentation or a book that needs admonitions, includes and cross-references without hand-writing DocBook.
Convert AsciiDoc to Markdown when a document is moving to a tool or audience that only understands Markdown, accepting that admonitions, includes and cross-references have no Markdown equivalent.
What is an HDR file?#
An HDR file stores a high-dynamic-range raster image using Radiance's RGBE encoding, which packs red, green and blue mantissas with one shared exponent per pixel so a scene can hold a far wider range of brightness than a standard 8-bit image.
Reach for HDR when you need a compact high-dynamic-range environment map or lighting reference that most 3D tools and renderers can read without a plugin.
Convert HDR to OpenEXR when a VFX pipeline needs true floating-point precision, an alpha channel or multiple layers in one file, or convert it to JPEG or PNG once the image has been tone-mapped for a normal display.
AsciiDoc to HDR questions people ask#
What's the difference between AsciiDoc and Markdown?
AsciiDoc is a plain-text markup built for technical documentation, with admonitions, file includes and cross-references defined in the syntax itself, where Markdown has none of these without an extension or raw HTML. AsciiDoc is correspondingly more to learn, and far fewer tools render it without going through a processor like Asciidoctor first.
What program opens an ADOC file?
An ADOC file is plain text, so any text editor opens it, but seeing it rendered means running it through Asciidoctor or an editor with an AsciiDoc preview plugin, such as VS Code's AsciiDoc extension or IntelliJ IDEA's AsciiDoc plugin. GitHub also renders .adoc files directly in a repository.
Does AsciiDoc convert cleanly to Markdown?
Basic AsciiDoc, headings, paragraphs, lists, emphasis, converts to Markdown with little loss. Admonition blocks, include directives and cross-references have no Markdown equivalent, so a conversion either drops them or flattens them into plain text and a broken link.
What is an HDR file used for?
An HDR file most often stores an environment map or lighting reference for 3D rendering, since Radiance's RGBE encoding was built for the Radiance lighting-simulation software. Photographers also use the .hdr extension for panoramas merged from several exposures, before tone-mapping the result down to a normal image.