RST to HDR Converter
FileFlip converts RST 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 RST file to HDR?#
- Drop your RST 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 RST to HDR lose quality?#
Yes, in the sense that text stops being text. Each RST 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 RST files online?#
Yes, because nothing is uploaded. FileFlip converts RST 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 RST to HDR actually does to the file#
Converting RST 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: RST → 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 RST file?#
An RST file holds reStructuredText, the markup David Goodger designed in 2001 for Python documentation, where directives and interpreted text roles extend the syntax with cross-references, footnotes and generated content that Markdown has no built-in equivalent for.
Write in reStructuredText for Python documentation or any Sphinx-built site that needs directives, cross-references and generated indexes.
Convert reStructuredText to Markdown when the destination lives outside the Sphinx or Python ecosystem, since most directives don't have a 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.
RST to HDR questions people ask#
What is reStructuredText used for?
reStructuredText is the markup behind Python's own documentation and most Sphinx-built documentation sites, chosen because PEP 287 made it the standard format for Python docstrings. Its directive system lets a project define custom content types, which is why documentation with heavy cross-referencing tends to land on it over Markdown.
What's the difference between RST and Markdown?
reStructuredText defines directives and interpreted text roles as a formal extension mechanism, where Markdown relies on each implementation inventing its own extensions. RST is also more strictly specified, so a Docutils-conformant file parses the same way everywhere, at the cost of a more verbose syntax than Markdown's.
Can I convert RST to Markdown without losing anything?
Headings, paragraphs, lists and basic emphasis convert from reStructuredText to Markdown cleanly. Directives, most notably Sphinx-specific ones like toctree or code-block with language-aware highlighting, plus footnotes and substitution definitions, have no direct Markdown equivalent and either get dropped or flattened to plain text.
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.