Exporting for the Web¶
Many browsers, including Firefox and Chromium-based browsers,
will not load exported projects when opened locally per
file:// protocol. To get around this, use a local server.
Python offers an easy method to start a local server.
python -m SimpleHTTPServer with Python 2 or
python -m http.server with Python 3 to serve the
current working directory at
Until the OpenGL ES 3 renderer is removed from Godot in favor of Vulkan, HTML5 export uses WebGL 2 when the GLES3 option is selected.
Usage of WebGL 2 is not recommended due to its expected removal from Godot without replacement.
WebGL 2 is not supported in all browsers. Firefox and Chromium (Chrome, Opera) are the most popular supported browsers, Safari and Edge do not work. On iOS, all browsers are based on WebKit (i.e. Safari), so they will also not work.
Godot’s WebGL 2 renderer has issues with 3D and is no longer maintained.
For security and privacy reasons, many features that work effortlessly on native platforms are more complicated on the web platform. Following is a list of limitations you should be aware of when porting a Godot game to the web.
Full screen and mouse capture¶
Browsers do not allow arbitrarily entering full screen. The same goes for
capturing the cursor. Instead, these actions have to occur as a response to
a pressed input event callback such as
Querying the Input singleton is not sufficient, the relevant
input event must currently be active.
For the same reason, the full screen project setting doesn’t work unless the engine is started from within a valid input event handler. This requires customization of the HTML page.
Chrome restricts how websites may play audio. It may be necessary for the player to click or tap or press a key to enable audio.
Google offers additional information about their Web Audio autoplay policies.
The HTTP classes have several restrictions on the HTML5 platform:
- Accessing or changing the
StreamPeeris not possible
- Threaded/Blocking mode is not available
- Cannot progress more than once per frame, so polling in a loop will freeze
- No chunked responses
- Host verification cannot be disabled
- Subject to same-origin policy
.html file must not be reused¶
Each project must generate their own HTML file. On export, several text placeholders are replaced in the generated HTML file specifically for the given export options. Any direct modifications to the generated HTML file will be lost in future exports. To customize the generated file, see Customizing the Web export HTML page.
Boot splash is not displayed¶
The default HTML page does not display the boot splash while loading. However, the image is exported as a PNG file, so custom HTML pages can display it.
The following functionality is currently unavailable on the HTML5 platform:
Check the list of open HTML5 issues on Github to see if the functionality you’re interested in has an issue yet. If not, open one to communicate your interest.
Serving the files¶
Exporting for the web generates several files to be served from a web server, including a default HTML page for presentation. A custom HTML file can be used, see Customizing the Web export HTML page.
.html file can be used as
DirectoryIndex in Apache
servers and can be renamed to e.g.
index.html at any time, its name is
never depended on by default.
The HTML page draws the game at maximum size within the browser window.
This way it can be inserted into an
<iframe> with the game’s size, as is
common on most web game hosting sites.
The other exported files are served as they are, next to the
names unchanged. The
.wasm file is a binary WebAssembly module implementing
the engine. The
.pck file is the Godot main pack containing your game. The
.js file contains start-up code and is used by the
.html file to access
the engine. The
.png file contains the boot splash image. It is not used in
the default HTML page, but is included for
custom HTML pages.
.pck file is binary, usually delivered with the MIME-type
.wasm file is delivered as
Delivering the WebAssembly module (
.wasm) with a MIME-type
other than application/wasm can prevent some start-up
Delivering the files with server-side compression is recommended especially for
.wasm files, which are usually large in size.
The WebAssembly module compresses particularly well, down to around a quarter
of its original size with gzip compression.
If a runnable web export template is available, a button appears between the Stop scene and Play edited Scene buttons in the editor to quickly open the game in the default browser for testing.
If a path to a Custom HTML shell file is given, it will be used instead of the default HTML page. See Customizing the Web export HTML page.
Head Include is appended into the
<head> element of the generated
HTML page. This allows to, for example, load webfonts and third-party
In web builds, the
This allows interacting with the browser in ways not possible with script
languages integrated into Godot.
eval() under certain circumstances:
HTML5 export templates may be built without support for the singleton. With such
templates, and on platforms other than HTML5, calling
null. The availability of the singleton can be checked with the
GDScript’s multi-line strings, surrounded by 3 quotes
""" as in
eval method also accepts a second, optional Boolean argument, which
specifies whether to execute the code in the global execution context,
false to prevent polluting the global namespace: