# Can we add a loss function to yolo?

**URL:** <https://community.ultralytics.com/t/can-we-add-a-loss-function-to-yolo/1782>\
**Category:** YOLO\
**Tags:** question, code\
**Created:** [January 30, 2026, 12:31pm UTC](https://community.ultralytics.com/t/can-we-add-a-loss-function-to-yolo/1782 "2026-01-30T12:31:29Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![hanyunuk](https://avatars.discourse-cdn.com/v4/letter/h/f08c70/32.png) [@hanyunuk](https://community.ultralytics.com/u/hanyunuk)\
**Post date:** [January 30, 2026, 12:31pm UTC](https://community.ultralytics.com/t/can-we-add-a-loss-function-to-yolo/1782/1 "2026-01-30T12:31:29Z")

</div>

I’m planning to add a loss function to perform 3D recognition and other tasks. I’m also preparing a dataset accordingly. Is it possible to add a loss function?

---

<div class="post-metadata">

**Author:** ![BurhanQ](https://sea1.discourse-cdn.com/flex001/user_avatar/community.ultralytics.com/burhanq/32/7_2.png) [@BurhanQ](https://community.ultralytics.com/u/BurhanQ)\
**Post date:** [January 30, 2026, 12:36pm UTC](https://community.ultralytics.com/t/can-we-add-a-loss-function-to-yolo/1782/2 "2026-01-30T12:36:41Z")

</div>

Yes, you can modify, or likely in your case create a new one, the `init_criterion` method for the task model. Here’s the [method](https://github.com/ultralytics/ultralytics/blob/a8b639bc35aa3d43efdde6691e5706a5525d8db6/ultralytics/nn/tasks.py#L510) for the detect task, and here’s the [detection loss class definition](https://github.com/ultralytics/ultralytics/blob/a8b639bc35aa3d43efdde6691e5706a5525d8db6/ultralytics/utils/loss.py#L333). So you’d likely need to create a `ThreeDModel` and `ThreeDLoss` class follow a similar design pattern.

---

<div class="post-metadata">

**Author:** ![hanyunuk](https://avatars.discourse-cdn.com/v4/letter/h/f08c70/32.png) [@hanyunuk](https://community.ultralytics.com/u/hanyunuk)\
**Post date:** [January 30, 2026, 12:52pm UTC](https://community.ultralytics.com/t/can-we-add-a-loss-function-to-yolo/1782/3 "2026-01-30T12:52:38Z")

</div>

```auto
Do I also need to modify files like head.py, dataset.py, Loss.py, and pred.py?

```

---

<div class="post-metadata">

**Author:** ![BurhanQ](https://sea1.discourse-cdn.com/flex001/user_avatar/community.ultralytics.com/burhanq/32/7_2.png) [@BurhanQ](https://community.ultralytics.com/u/BurhanQ)\
**Post date:** [January 30, 2026, 12:58pm UTC](https://community.ultralytics.com/t/can-we-add-a-loss-function-to-yolo/1782/4 "2026-01-30T12:58:00Z")

</div>

You will probably need to make lots of edits to fully integrate a 3D detection model yes.