Command Line Arguments

Blender 4.4
Usage: blender [args ...] [file] [args ...]

Render Options

-b, --background

Run in background (often used for UI-less rendering).

The audio device is disabled in background-mode by default and can be re-enabled by passing in -setaudio Default afterwards.

-a, --render-anim

Render frames from start to end (inclusive).

-S, --scene <name>

Set the active scene <name> for rendering.

-f, --render-frame <frame>

Render frame <frame> and save it.

  • +<frame> start frame relative, -<frame> end frame relative.

  • A comma separated list of frames can also be used (no spaces).

  • A range of frames can be expressed using .. separator between the first and last frames (inclusive).

-s, --frame-start <frame>

Set start to frame <frame>, supports +/- for relative frames too.

-e, --frame-end <frame>

Set end to frame <frame>, supports +/- for relative frames too.

-j, --frame-jump <frames>

Set number of frames to step forward after each rendered frame.

-o, --render-output <path>

Set the render path and file name. Use // at the start of the path to render relative to the blend-file.

The # characters are replaced by the frame number, and used to define zero padding.

  • animation_##_test.png becomes animation_01_test.png

  • test-######.png becomes test-000001.png

When the filename does not contain #, the suffix #### is added to the filename.

The frame number will be added at the end of the filename, eg:

blender -b animation.blend -o //render_ -F PNG -x 1 -a

//render_ becomes //render_####, writing frames as //render_0001.png

-E, --engine <engine>

Specify the render engine. Use -E help to list available engines.

-t, --threads <threads>

Use amount of <threads> for rendering and other operations [1-1024], 0 to use the systems processor count.

Cycles Render Options

Cycles add-on options must be specified following a double dash.

--cycles-device <device>

Set the device used for rendering. Valid options are: CPU CUDA OPTIX HIP ONEAPI METAL.

Append +CPU to a GPU device to render on both CPU and GPU.

Example:

blender -b file.blend -f 20 -- --cycles-device OPTIX
--cycles-print-stats

Log statistics about render memory and time usage.

Format Options

-F, --render-format <format>

Set the render format. Valid options are: TGA RAWTGA JPEG IRIS AVIRAW AVIJPEG PNG BMP HDR TIFF.

Formats that can be compiled into Blender, not available on all systems: OPEN_EXR OPEN_EXR_MULTILAYER FFMPEG CINEON DPX JP2 WEBP.

-x, --use-extension <bool>

Set option to add the file extension to the end of the file.

Animation Playback Options

-a <options> <file(s)>

Instead of showing Blender’s user interface, this runs Blender as an animation player, to view movies and image sequences rendered in Blender (ignored if -b is set).

Playback Arguments:

-p <sx> <sy>

Open with lower left corner at <sx>, <sy>.

-m

Read from disk (Do not buffer).

-f <fps> <fps_base>

Specify FPS to start with.

-j <frame>

Set frame step to <frame>.

-s <frame>

Play from <frame>.

-e <frame>

Play until <frame>.

-c <cache_memory>

Amount of memory in megabytes to allow for caching images during playback. Zero disables (clamping to a fixed number of frames instead).

Window Options

-w, --window-border

Force opening with borders.

-W, --window-fullscreen

Force opening in full-screen mode.

-p, --window-geometry <sx> <sy> <w> <h>

Open with lower left corner at <sx>, <sy> and width and height as <w>, <h>.

-M, --window-maximized

Force opening maximized.

-con, --start-console

Start with the console window open (ignored if -b is set), (Windows only).

--no-native-pixels

Do not use native pixel size, for high resolution displays (MacBook Retina).

--no-window-focus

Open behind other windows and without taking focus.

Python Options

-y, --enable-autoexec

Enable automatic Python script execution.

-Y, --disable-autoexec

Disable automatic Python script execution (Python-drivers & startup scripts), (default).

-P, --python <filepath>

Run the given Python script file.

--python-text <name>

Run the given Python script text block.

--python-expr <expression>

Run the given expression as a Python script.

--python-console

Run Blender with an interactive console.

--python-exit-code <code>

Set the exit-code in [0..255] to exit if a Python exception is raised (only for scripts executed from the command line), zero disables.

--python-use-system-env

Allow Python to use system environment variables such as PYTHONPATH and the user site-packages directory.

--addons <addon(s)>

Comma separated list (no spaces) of add-ons to enable in addition to any default add-ons.

Network Options

--online-mode

Allow internet access, overriding the preference.

--offline-mode

Disallow internet access, overriding the preference.

Logging Options

--log <match>

Enable logging categories, taking a single comma separated argument. Multiple categories can be matched using a .* suffix, so --log "wm.*" logs every kind of window-manager message. Sub-string can be matched using a * prefix and suffix, so --log "*undo*" logs every kind of undo-related message. Use “^” prefix to ignore, so --log "*,^wm.operator.*" logs all except for wm.operators.* Use “*” to log everything.

--log-level <level>

Set the logging verbosity level (higher for more details) defaults to 1, use -1 to log all levels.

--log-show-basename

Only show file name in output (not the leading path).

--log-show-backtrace

Show a back trace for each log message (debug builds only).

--log-show-timestamp

Show a timestamp for each log message in seconds since start.

--log-file <filepath>

Set a file to output the log to.

Debug Options

-d, --debug

Turn debugging on.

  • Enables memory error detection

  • Disables mouse grab (to interact with a debugger in some cases)

  • Keeps Python’s sys.stdin rather than setting it to None

--debug-value <value>

Set debug value of <value> on startup.

--debug-events

Enable debug messages for the event system.

--debug-ffmpeg

Enable debug messages from FFmpeg library.

--debug-handlers

Enable debug messages for event handling.

--debug-libmv

Enable debug messages from libmv library.

--debug-cycles

Enable debug messages from Cycles.

--debug-memory

Enable fully guarded memory allocation and debugging.

--debug-jobs

Enable time profiling for background jobs.

--debug-python

Enable debug messages for Python.

--debug-depsgraph

Enable all debug messages from dependency graph.

--debug-depsgraph-eval

Enable debug messages from dependency graph related on evaluation.

--debug-depsgraph-build

Enable debug messages from dependency graph related on graph construction.

--debug-depsgraph-tag

Enable debug messages from dependency graph related on tagging.

--debug-depsgraph-no-threads

Switch dependency graph to a single threaded evaluation.

--debug-depsgraph-time

Enable debug messages from dependency graph related on timing.

--debug-depsgraph-pretty

Enable colors for dependency graph debug messages.

--debug-depsgraph-uid

Verify validness of session-wide identifiers assigned to ID data-blocks.

--debug-ghost

Enable debug messages for Ghost (Linux only).

--debug-wintab

Enable debug messages for Wintab.

--debug-gpu

Enable GPU debug context and information for OpenGL 4.3+.

--debug-gpu-force-workarounds

Enable workarounds for typical GPU issues and disable all GPU extensions.

--debug-gpu-compile-shaders

Compile all statically defined shaders to test platform compatibility.

--debug-gpu-scope-capture

Capture the GPU commands issued inside the give scope name.

--debug-gpu-renderdoc

Enable RenderDoc integration for GPU frame grabbing and debugging.

--debug-wm

Enable debug messages for the window manager, shows all operators in search, shows keymap errors.

--debug-xr

Enable debug messages for virtual reality contexts. Enables the OpenXR API validation layer, (OpenXR) debug messages and general information prints.

--debug-xr-time

Enable debug messages for virtual reality frame rendering times.

--debug-all

Enable all debug messages.

--debug-io

Enable debug messages for I/O (Collada, …).

--debug-fpe

Enable floating-point exceptions.

--debug-exit-on-error

Immediately exit when internal errors are detected.

--debug-freestyle

Enable debug messages for Freestyle.

--disable-crash-handler

Disable the crash handler.

--disable-abort-handler

Disable the abort handler.

--verbose <verbose>

Set the logging verbosity level for debug messages that support it.

-q, --quiet

Suppress status printing (warnings & errors are still printed).

GPU Options

--gpu-backend

Force to use a specific GPU backend. Valid options: vulkan (experimental), metal, opengl.

--gpu-compilation-subprocesses

Override the Max Compilation Subprocesses setting (OpenGL only).

Misc Options

--open-last

Open the most recently opened blend file, instead of the default startup file.

--app-template <template>

Set the application template (matching the directory name), use default for none.

--factory-startup

Skip reading the startup.blend in the users home directory.

--enable-event-simulate

Enable event simulation testing feature bpy.types.Window.event_simulate.

--env-system-datafiles

Set the BLENDER_SYSTEM_DATAFILES environment variable.

--env-system-scripts

Set the BLENDER_SYSTEM_SCRIPTS environment variable.

--env-system-extensions

Set the BLENDER_SYSTEM_EXTENSIONS environment variable.

--env-system-python

Set the BLENDER_SYSTEM_PYTHON environment variable.

-noaudio

Force sound system to None.

-setaudio

Force sound system to a specific device. None Default SDL OpenAL CoreAudio JACK PulseAudio WASAPI.

-c, --command <command>

Run a command which consumes all remaining arguments. Use -c help to list all other commands. Pass --help after the command to see its help text.

This implies --background mode.

-h, --help

Print this help text and exit.

/?

Print this help text and exit (Windows only).

-r, --register

Register blend-file extension for current user, then exit (Windows & Linux only).

--register-allusers

Register blend-file extension for all users, then exit (Windows & Linux only).

--unregister

Unregister blend-file extension for current user, then exit (Windows & Linux only).

--unregister-allusers

Unregister blend-file extension for all users, then exit (Windows & Linux only).

-v, --version

Print Blender version and exit.

--

End option processing, following arguments passed unchanged. Access via Python’s sys.argv.

Other Options

--disable-depsgraph-on-file-load

Backround mode: Do not systematically build and evaluate ViewLayers’ dependency graphs when loading a blendfile in background mode (-b or -c options).

Scripts requiring evaluated data then need to explicitly ensure that an evaluated depsgraph is available (e.g. by calling depsgraph = context.evaluated_depsgraph_get()).

NOTE: this is a temporary option, in the future depsgraph will never be automatically generated on file load in background mode.

--disable-liboverride-auto-resync

Do not perform library override automatic resync when loading a new blendfile.

NOTE: this is an alternative way to get the same effect as when setting the No Override Auto Resync User Preferences Debug option.

Argument Parsing

Arguments must be separated by white space, eg:

blender -ba test.blend

…will exit since -ba is an unknown argument.

Argument Order

Arguments are executed in the order they are given. eg:

blender --background test.blend --render-frame 1 --render-output "/tmp"

…will not render to /tmp because --render-frame 1 renders before the output path is set.

blender --background --render-output /tmp test.blend --render-frame 1

…will not render to /tmp because loading the blend-file overwrites the render output that was set.

blender --background test.blend --render-output /tmp --render-frame 1

…works as expected.

Environment Variables

BLENDER_USER_RESOURCES:

Replace default directory of all user files. Other BLENDER_USER_* variables override when set.

BLENDER_USER_CONFIG:

Directory for user configuration files.

BLENDER_USER_SCRIPTS:

Directory for user scripts.

BLENDER_USER_EXTENSIONS:

Directory for user extensions.

BLENDER_USER_DATAFILES:

Directory for user data files (icons, translations, ..).

BLENDER_SYSTEM_RESOURCES:

Replace default directory of all bundled resource files.

BLENDER_SYSTEM_SCRIPTS:

Directories to add extra scripts.

BLENDER_SYSTEM_EXTENSIONS:

Directory for system extensions repository.

BLENDER_SYSTEM_DATAFILES:

Directory to replace bundled datafiles.

BLENDER_SYSTEM_PYTHON:

Directory to replace bundled Python libraries.

BLENDER_CUSTOM_SPLASH:

Full path to an image that replaces the splash screen.

BLENDER_CUSTOM_SPLASH_BANNER:

Full path to an image to overlay on the splash screen.

OCIO:

Path to override the OpenColorIO configuration file.

TEMP:

Store temporary files here (MS-Windows).

TMPDIR:

Store temporary files here (UNIX Systems). The path must reference an existing directory or it will be ignored.