# Hugging Face Transformers v4.21.0 — Release & Upgrade Intelligence
- **Product:** Hugging Face Transformers (https://huggingface.co)
- **Version:** v4.21.0
- **Released:** Jul 27, 2022
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/transformers/updates/v4.21.0/

## Executive Summary (TL;DR)
Hugging Face Transformers v4.21.0. Source highlight: TensorFlow XLA Text Generation

## New Features
- Add OWL-ViT model for zero-shot object detection  by @alaradirik in #17938
- add MobileViT model  by @hollance in #17354
- Add MVP model  by @StevenTang1998 in #17787
- Add CodeGen model  by @rooa in #17443
- Add UL2 (just docs)  by @patrickvonplaten in #17740
- Add TF DeiT implementation  by @amyeroberts in #17806

## Improvements
- [SegFormer] TensorFlow port  by @sayakpaul in #17910
- TF implementation of RegNets  by @ariG23498 in #17554
- TF Sharded  by @ArthurZucker in #17713
- Flax t5 Encoder  by @crystina-z in #17784
- Flax sharded  by @ArthurZucker in #17760

## Bug Fixes
- Fix OwlViT tests  by @sgugger in #18253
- Translation/debugging  by @nickprock in #18230
- [EncoderDecoder] Improve docs  by @NielsRogge in #18271
- [DETR] Improve code examples  by @NielsRogge in #18262
- patch for smddp import  by @carolynwang in #18244
- Fix Sylvain's nits on the original KerasMetricCallback PR  by @Rocketknight1 in #18300

## Upgrade Command
```bash
python -m pip install 'transformers==4.21.0'
```