# Hugging Face Transformers v5.5.0 — Release & Upgrade Intelligence
- **Product:** Hugging Face Transformers (https://huggingface.co)
- **Version:** v5.5.0
- **Released:** Apr 02, 2026
- **Impact Score:** 7/10
- **Breaking Changes:** Source flagged
- **Canonical Analysis:** https://changelogs.us/transformers/updates/v5.5.0/

## Executive Summary (TL;DR)
Hugging Face Transformers v5.5.0. Source highlight: Gemma 4 is a multimodal model with pretrained and instruction-tuned variants, available in 1B, 13B, and 27B parameters. The architecture is mostly the same as the previous Gemma versions. The key differences are a vision processor that can output images of fixed token budget and a spatial 2D RoPE to

## Breaking Changes & Deprecations
- Breaking changes Mamba and hybrid model caches are now first-class native citizens in the library, so users working with Mamba-based or hybrid (Mamba + attention) models should update their code to use the new native cache classes instead of any previous workarounds.

## New Features
- Add Music Flamingo (#43538) by @lashahub in #43538
- refactor: added cache in check_repo (#45012) by @tarekziade in [#45012]
- feature: added import complexity checker (#45013)
- refactor: added cache in check_repo (#45012)
- Add Music Flamingo (#43538)

## Bug Fixes
- The total number of pixels must fit within a patch budget
- Both height and width must be divisible by **48** (= patch size 16 × pooling kernel 3)
- Fix explicit local code resolution for tokenizers and image processors (#45169) by @hmellor in [#45169]
- fix bug for janus model image generation (#45044) by @kaixuanliu in [#45044]
- [Bugfix] Remove incorrect torchvision requirement from PIL backend image processors (#45045) by @Lidang-Jiang in [#45045]
- chore: Fix mlinter cache location (#45052) by @tarekziade in [#45052]

## Upgrade Command
```bash
python -m pip install 'transformers==5.5.0'
```