docs/en/reference/utils/callbacks/base.md

metadata

description: >-
  Discover the essential base callbacks in Ultralytics for training, validation,
  prediction, and exporting models efficiently.
keywords: >-
  Ultralytics, base callbacks, training, validation, prediction, model export,
  ML, machine learning, deep learning

Reference for ultralytics/utils/callbacks/base.py

!!! note

This file is available at [https://github.com/ultralytics/ultralytics/blob/main/ultralytics/utils/callbacks/base.py](https://github.com/ultralytics/ultralytics/blob/main/ultralytics/utils/callbacks/base.py). If you spot a problem please help fix it by [contributing](https://docs.ultralytics.com/help/contributing/) a [Pull Request](https://github.com/ultralytics/ultralytics/edit/main/ultralytics/utils/callbacks/base.py) 🛠️. Thank you 🙏!

::: ultralytics.utils.callbacks.base.on_pretrain_routine_start

---

::: ultralytics.utils.callbacks.base.on_pretrain_routine_end

---

::: ultralytics.utils.callbacks.base.on_train_start

---

::: ultralytics.utils.callbacks.base.on_train_epoch_start

---

::: ultralytics.utils.callbacks.base.on_train_batch_start

---

::: ultralytics.utils.callbacks.base.optimizer_step

---

::: ultralytics.utils.callbacks.base.on_before_zero_grad

---

::: ultralytics.utils.callbacks.base.on_train_batch_end

---

::: ultralytics.utils.callbacks.base.on_train_epoch_end

---

::: ultralytics.utils.callbacks.base.on_fit_epoch_end

---

::: ultralytics.utils.callbacks.base.on_model_save

---

::: ultralytics.utils.callbacks.base.on_train_end

---

::: ultralytics.utils.callbacks.base.on_params_update

---

::: ultralytics.utils.callbacks.base.teardown

---

::: ultralytics.utils.callbacks.base.on_val_start

---

::: ultralytics.utils.callbacks.base.on_val_batch_start

---

::: ultralytics.utils.callbacks.base.on_val_batch_end

---

::: ultralytics.utils.callbacks.base.on_val_end

---

::: ultralytics.utils.callbacks.base.on_predict_start

---

::: ultralytics.utils.callbacks.base.on_predict_batch_start

---

::: ultralytics.utils.callbacks.base.on_predict_batch_end

---

::: ultralytics.utils.callbacks.base.on_predict_postprocess_end

---

::: ultralytics.utils.callbacks.base.on_predict_end

---

::: ultralytics.utils.callbacks.base.on_export_start

---

::: ultralytics.utils.callbacks.base.on_export_end

---

::: ultralytics.utils.callbacks.base.get_default_callbacks

---

::: ultralytics.utils.callbacks.base.add_integration_callbacks