# T5v1.1 tokenizer legacy=False

**URL:** <https://discuss.huggingface.co/t/t5v1-1-tokenizer-legacy-false/74250>\
**Category:** 🤗Tokenizers\
**Created:** [February 22, 2024, 3:36am UTC](https://discuss.huggingface.co/t/t5v1-1-tokenizer-legacy-false/74250 "2024-02-22T03:36:16Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Nevermetyou](https://sea2.discourse-cdn.com/hellohellohello/user_avatar/discuss.huggingface.co/nevermetyou/32/21618_2.png) [@Nevermetyou](https://discuss.huggingface.co/u/Nevermetyou)\
**Post date:** [February 22, 2024, 3:36am UTC](https://discuss.huggingface.co/t/t5v1-1-tokenizer-legacy-false/74250/1 "2024-02-22T03:36:16Z")

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Hello, I am using t5v1.1 right now and have a question about the arg `legacy`. The only thing I know is it involves fixing some bugs.

> - **legacy** (`bool`, _optional_) — Whether or not the `legacy` behaviour of the tokenizer should be used. Legacy is before the merge of #24622 and #25224 which includes fixes to properly handle tokens that appear after special tokens. A simple example:
> - `legacy=True`:

But should I set it to false to use new behavior??