๐ Summary
Ultralytics 8.4.149 improves training reliability, export compatibility, and Platform documentationโespecially for resumed runs and third-party integrations. ๐
๐ Key Changes
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More reliable training resume behavior ๐
- Resuming from a checkpoint now preserves the dataset stored in that checkpoint instead of unexpectedly switching to the default COCO8 dataset.
- An explicitly provided
data=argument still takes priority. - Missing datasets now produce the expected dataset-not-found error rather than causing optimizer or model-shape failures.
- Resuming checkpoints created with AMP disabled no longer attempts to load an empty AMP scaler state.
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Safer ONNX CUDA fallback โ๏ธ
- CUDA availability is now checked after ONNX Runtime creates its inference session.
- If the CUDA execution provider is unavailable, inference automatically falls back to CPU with a clear warning instead of crashing.
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Ray Tune compatibility improvements ๐
- Ray Tune integration now verifies that a compatible Ray version is installed.
- Training metrics are reported through the current Ray Tune API, reducing failures with newer Ray releases.
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More robust Weights & Biases runs ๐
- Automatically generated W&B run names are limited to 64 characters, preventing crashes caused by overly long names.
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Improved invalid-argument errors ๐ ๏ธ
- CLI help is logged separately from the syntax error message, helping the core error remain visible even when logs are truncated.
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RT-DETR LiteRT export and inference fixes ๐ฑ
- RT-DETR outputs are no longer incorrectly coordinate-normalized during LiteRT export or inference.
- This brings LiteRT detection metrics much closer to ONNX results, improving accuracy across Python and JavaScript/npm workflows.
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SAM 3.1 becomes the default Platform smart annotation model โจ
- Ultralytics Platform now lists SAM 3.1 as the default smart annotation model, while SAM 3 and SAM 2.1 remain available.
- SAM 3.1 image prediction support and current limitations, including unsupported Object Multiplex video tracking, are documented.
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Platform AutoTrain documentation reorganized ๐
- AutoTrain has moved to Platform โ Train โ AutoTrain.
- The documentation now emphasizes baseline creation, controlled comparisons, experiment review, billing, and team workspace usage.
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Package version updated ๐ฆ
- Version bumped to
8.4.149.
- Version bumped to
๐ฏ Purpose & Impact
- Fewer training crashes: Users can resume interrupted jobs more confidently, even when datasets have moved or AMP settings differ.
- Better deployment resilience: ONNX models requested on CUDA systems can continue running on CPU when CUDA support is unavailable.
- More dependable integrations: Ray Tune and W&B workflows are less likely to fail because of API differences or naming limits.
- Improved edge deployment accuracy: RT-DETR models exported to LiteRT should produce results more consistent with ONNX, benefiting mobile and browser applications.
- Simpler annotation workflows: New users on Ultralytics Platform get SAM 3.1 by default for high-quality image annotation, with alternative SAM models available for speed or compatibility.
- Clearer experimentation guidance: The reorganized AutoTrain documentation makes it easier to run repeatable training experiments and choose the next improvement step.
What's Changed
- List SAM 3.1 as the default Platform smart annotation model by @glenn-jocher in #26145
- Move AutoTrain documentation under Platform Train by @JaviChulvi in #26146
- Fix normalization conditions in DETR models for LiteRT export and inference by @onuralpszr in #26142
- Fix resume, ONNX CUDA fallback, Ray Tune and W&B training crashes by @glenn-jocher in #26148
Full Changelog: v8.4.148...v8.4.149