diff --git a/fooocus_version.py b/fooocus_version.py
index 271ba39..6acc275 100644
--- a/fooocus_version.py
+++ b/fooocus_version.py
@@ -1 +1 @@
-version = '2.1.818'
+version = '2.1.819'
diff --git a/modules/advanced_parameters.py b/modules/advanced_parameters.py
index 46d074a..1547a87 100644
--- a/modules/advanced_parameters.py
+++ b/modules/advanced_parameters.py
@@ -1,14 +1,14 @@
-adm_scaler_positive, adm_scaler_negative, adm_scaler_end, adaptive_cfg, sampler_name,  \
+disable_preview, adm_scaler_positive, adm_scaler_negative, adm_scaler_end, adaptive_cfg, sampler_name,  \
     scheduler_name, generate_image_grid, overwrite_step, overwrite_switch, overwrite_width, overwrite_height, \
     overwrite_vary_strength, overwrite_upscale_strength, \
     mixing_image_prompt_and_vary_upscale, mixing_image_prompt_and_inpaint, \
     debugging_cn_preprocessor, skipping_cn_preprocessor, controlnet_softness, canny_low_threshold, canny_high_threshold, inpaint_engine, \
     refiner_swap_method, \
-    freeu_enabled, freeu_b1, freeu_b2, freeu_s1, freeu_s2 = [None] * 27
+    freeu_enabled, freeu_b1, freeu_b2, freeu_s1, freeu_s2 = [None] * 28
 
 
 def set_all_advanced_parameters(*args):
-    global adm_scaler_positive, adm_scaler_negative, adm_scaler_end, adaptive_cfg, sampler_name, \
+    global disable_preview, adm_scaler_positive, adm_scaler_negative, adm_scaler_end, adaptive_cfg, sampler_name, \
         scheduler_name, generate_image_grid, overwrite_step, overwrite_switch, overwrite_width, overwrite_height, \
         overwrite_vary_strength, overwrite_upscale_strength, \
         mixing_image_prompt_and_vary_upscale, mixing_image_prompt_and_inpaint, \
@@ -16,7 +16,7 @@ def set_all_advanced_parameters(*args):
         refiner_swap_method, \
         freeu_enabled, freeu_b1, freeu_b2, freeu_s1, freeu_s2
 
-    adm_scaler_positive, adm_scaler_negative, adm_scaler_end, adaptive_cfg, sampler_name, \
+    disable_preview, adm_scaler_positive, adm_scaler_negative, adm_scaler_end, adaptive_cfg, sampler_name, \
         scheduler_name, generate_image_grid, overwrite_step, overwrite_switch, overwrite_width, overwrite_height, \
         overwrite_vary_strength, overwrite_upscale_strength, \
         mixing_image_prompt_and_vary_upscale, mixing_image_prompt_and_inpaint, \
diff --git a/modules/core.py b/modules/core.py
index 865f5d3..4586d7c 100644
--- a/modules/core.py
+++ b/modules/core.py
@@ -16,6 +16,7 @@ import fcbh.controlnet
 import modules.sample_hijack
 import fcbh.samplers
 import fcbh.latent_formats
+import modules.advanced_parameters
 
 from fcbh.sd import load_checkpoint_guess_config
 from nodes import VAEDecode, EmptyLatentImage, VAEEncode, VAEEncodeTiled, VAEDecodeTiled, \
@@ -319,7 +320,7 @@ def ksampler(model, positive, negative, latent, seed=None, steps=30, cfg=7.0, sa
     def callback(step, x0, x, total_steps):
         fcbh.model_management.throw_exception_if_processing_interrupted()
         y = None
-        if previewer is not None:
+        if previewer is not None and not modules.advanced_parameters.disable_preview:
             y = previewer(x0, previewer_start + step, previewer_end)
         if callback_function is not None:
             callback_function(previewer_start + step, x0, x, previewer_end, y)
diff --git a/update_log.md b/update_log.md
index 5eb6fa5..57b1865 100644
--- a/update_log.md
+++ b/update_log.md
@@ -1,3 +1,7 @@
+# 2.1.819
+
+* Allow disabling preview in dev tools.
+
 # 2.1.818
 
 * Fix preset lora failed to load when the weight is exactly one.
diff --git a/webui.py b/webui.py
index 3c0ce37..8e106e1 100644
--- a/webui.py
+++ b/webui.py
@@ -340,11 +340,12 @@ with shared.gradio_root:
                         overwrite_upscale_strength = gr.Slider(label='Forced Overwrite of Denoising Strength of "Upscale"',
                                                                minimum=-1, maximum=1.0, step=0.001, value=-1,
                                                                info='Set as negative number to disable. For developer debugging.')
-
                         inpaint_engine = gr.Dropdown(label='Inpaint Engine',
                                                      value=modules.config.default_inpaint_engine_version,
                                                      choices=flags.inpaint_engine_versions,
                                                      info='Version of Fooocus inpaint model')
+                        disable_preview = gr.Checkbox(label='Disable Preview', value=False,
+                                                      info='Disable preview during generation.')
 
                     with gr.Tab(label='Control Debug'):
                         debugging_cn_preprocessor = gr.Checkbox(label='Debug Preprocessors', value=False,
@@ -375,7 +376,7 @@ with shared.gradio_root:
                         freeu_s2 = gr.Slider(label='S2', minimum=0, maximum=4, step=0.01, value=0.95)
                         freeu_ctrls = [freeu_enabled, freeu_b1, freeu_b2, freeu_s1, freeu_s2]
 
-                adps = [adm_scaler_positive, adm_scaler_negative, adm_scaler_end, adaptive_cfg, sampler_name,
+                adps = [disable_preview, adm_scaler_positive, adm_scaler_negative, adm_scaler_end, adaptive_cfg, sampler_name,
                         scheduler_name, generate_image_grid, overwrite_step, overwrite_switch, overwrite_width, overwrite_height,
                         overwrite_vary_strength, overwrite_upscale_strength,
                         mixing_image_prompt_and_vary_upscale, mixing_image_prompt_and_inpaint,