BSP File Format (.bsp)
A BSP file is a compiled Quake III Arena level: an entire map's world geometry, pre-partitioned into a binary space tree, along with its lightmaps, texture references and entity placements, not a model of a single object.
BSP at a glance#
| Full name | Quake III BSP level |
|---|---|
| File extension | .bsp |
| Category | 3D Models |
| Developer | id Software |
| First released | 1999 |
| Compression | Uncompressed |
| FileFlip support | FileFlip reads this format but does not write it |
What a .bsp file can hold#
These are the things a BSP file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.
| Textures and materials | Yes |
|---|
Strengths and limitations of BSP#
What BSP does well
- Geometry is pre-sorted into a binary space partition tree, so the engine can resolve visibility and draw order at load time instead of doing that work every frame
- Baked lightmaps travel inside the file, so a level looks exactly as its author lit it with no runtime lighting computation needed
- Entity placements, spawn points, lights, triggers, doors, live in the same file as the geometry that defines them
Where BSP falls short
- Holds an entire level rather than a single object, so opening one produces one large, non-editable mesh rather than a reusable prop
- The partition and visibility data are baked for one specific map layout, so there's no way to lift out a single room without rebuilding those structures
- Textures and shaders are referenced by name rather than embedded, so a BSP alone is missing the assets it needs unless its PK3 comes with it
Use BSP to ship or run a compiled Quake III Arena level; the original engine or a source port loads it together with its PK3 to render the map.
Convert a BSP file mainly to inspect or reuse its geometry outside the original game, since the format isn't meant to be edited directly; going back to the level editor's source .map file is the normal way to make changes.
How to open a .bsp file#
A .bsp file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts BSP into a format your machine already opens, and it does it in the browser tab rather than on a server.
| Platform | Programs that open it |
|---|---|
| Windows | GtkRadiant, NetRadiant |
| macOS | ioquake3, OpenArena |
| Linux | ioquake3, OpenArena, GtkRadiant, NetRadiant |
| Web | FileFlip |
BSP questions people ask#
What is a BSP file?
A BSP file is a compiled Quake III Arena level, holding the map's entire world geometry pre-sorted into a binary space partition tree along with its lightmaps and entity placements. It's a level, not a single model, so opening one gets you the whole map's geometry rather than a prop.
Can I get a single object or prop out of a BSP file?
Not directly. A BSP stores one specific map's geometry already merged and partitioned for that layout, so there's no clean way to pull out an individual piece without rebuilding the partition and visibility data from source. The original .map file the level was compiled from is the format actually meant for editing.
What opens BSP files today?
The open-source ioquake3 engine and games built on it, like OpenArena, load BSP files exactly as Quake III Arena did, and level editors such as GtkRadiant and NetRadiant compile and inspect them directly.
Converting BSP files#
Convert BSP to another format
FileFlip does not write .bsp files, so nothing on the site converts into this format. It works as a source only.
Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.