ComfyUI: ModuleNotFoundError: No module named 'tqdm' (fix)

ModuleNotFoundError: No module named 'tqdm' stops ComfyUI right at startup, before any model or node loads. We reproduced it on ComfyUI v0.37.0 and fixed it.

1. The error

ComfyUI v0.37.0 started in a venv where everything from requirements.txt is installed except tqdm:

python main.py
Traceback (most recent call last):
  File "/path/to/ComfyUI/main.py", line 35, in <module>
    from comfy_execution.progress import get_progress_state
  File "/path/to/ComfyUI/comfy_execution/progress.py", line 6, in <module>
    from tqdm import tqdm
ModuleNotFoundError: No module named 'tqdm'

ComfyUI exited with code 1 almost immediately: main.py line 35 imports comfy_execution/progress.py, which does from tqdm import tqdm at line 6. tqdm (the progress-bar library) is listed in ComfyUI's requirements.txt, and transformers, huggingface_hub and gguf depend on it too, so seeing it missing usually means the requirements were never installed into the Python that runs ComfyUI, or something uninstalled it.

2. Fix: install requirements.txt with the same Python

From the ComfyUI folder, using the Python that starts ComfyUI (your venv's python; in the Windows portable build, ..\python_embeded\python.exe run from inside the ComfyUI folder):

python -m pip install -r requirements.txt
Collecting tqdm (from -r requirements.txt (line 19))
  Downloading tqdm-4.70.1-py3-none-any.whl.metadata (57 kB)
Downloading tqdm-4.70.1-py3-none-any.whl (80 kB)
Installing collected packages: tqdm
Successfully installed tqdm-4.70.1

(pip also printed a dependency warning about packages of an unrelated custom node in our test venv; we left it out.) Started again, ComfyUI loaded all nodes and exited 0 (--quick-test-for-ci):

[INFO] Context impl SQLiteImpl.
[INFO] Will assume non-transactional DDL.
[INFO] Using RAM pressure cache.

If pip says tqdm is already installed and the error stays, you are installing into a different Python than the one running ComfyUI. See ComfyUI: No module named 'yaml' for how to find the right one.

Related: ComfyUI: No module named 'transformers' · ComfyUI: No module named 'torchsde' · ComfyUI: No module named 'sqlalchemy' · ComfyUI: No module named 'requests'

Frequently asked questions

Is tqdm required by ComfyUI?

Yes. It is in requirements.txt and comfy_execution/progress.py imports it during startup, so ComfyUI exits with code 1 without it.

I installed tqdm but still get the error. Why?

It went into a different Python. Run python -m pip with the same python (or python_embeded\python.exe) that starts ComfyUI.

Written with AI assistance. Measured on 2026-10-24 on Linux, CPython 3.11.17, pip 26.2.2: ComfyUI v0.37.0 with torch 2.9.0+cpu, without tqdm and after pip install -r requirements.txt (tqdm 4.70.1). Output pasted unedited except shortened paths and one omitted pip warning. PlainTables is our extension; ComfyUI and tqdm are free.