Command Line Arguments

Blender 3.1 Usage: blender [args …] [file] [args …]

Render Options

-b, --background

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

-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 [1-64], 0 for systems processor count.

Format Options

-F, --render-format <format>

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

Formats that can be compiled into Blender, not available on all systems: HDR TIFF OPEN_EXR OPEN_EXR_MULTILAYER MPEG CINEON DPX DDS JP2

-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 fullscreen 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 (default).

-Y, --disable-autoexec

Disable automatic Python script execution (pydrivers & startup scripts).

-P, --python <filename>

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 of add-ons (no spaces).

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 <filename>

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-uuid

Enable debug messages from dependency graph related on graph construction.

--debug-ghost

Enable debug messages for event handling.

--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-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.

--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.

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-python

Set the BLENDER_SYSTEM_PYTHON environment variable.

-noaudio

Force sound system to None.

-setaudio

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

-h, --help

Print this help text and exit.

/?

Print this help text and exit (Windows only).

-R

Register blend-file extension, then exit (Windows only).

-r

Silently register blend-file extension, then exit (Windows only).

-v, --version

Print Blender version and exit.

--

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

Other Options

--debug-freestyle

Enable debug messages for Freestyle.

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_CONFIG

Directory for user configuration files.

BLENDER_USER_SCRIPTS

Directory for user scripts.

BLENDER_SYSTEM_SCRIPTS

Directory for system wide scripts.

BLENDER_USER_DATAFILES

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

BLENDER_SYSTEM_DATAFILES

Directory for system wide data files.

BLENDER_SYSTEM_PYTHON

Directory for system Python libraries.

OCIO

Path to override the OpenColorIO config file.

TEMP

Store temporary files here.

TMP

or $TMPDIR Store temporary files here.