# Changing Tokenizer's max\_length gets weird result
**URL:**
**Author:**  [@Mapraw](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2FMapraw)%5C
**Post date:** [May 17, 2022, 4:33am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Fchanging-tokenizers-max-length-gets-weird-result%2F18029%2F1 "2022-05-17T04:33:06Z")
Hello, I try to tokenize the sentence with “bert-base-uncased” with 3 max\_length with these sentences " [‘I love it’, “You done”],[“Mary do”, “Dog eats paper”]" and it returns a lot of sentence with more max\_length than I set. Please, describe this phenomenon.
Please.
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**Author:**  [@cog](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2Fcog)%5C
**Post date:** [May 17, 2022, 6:45am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Fchanging-tokenizers-max-length-gets-weird-result%2F18029%2F3 "2022-05-17T06:45:12Z")
hi.
if you use it without ‘return\_overflowing\_token’, return successfully truncated token.
Also, i tried your same code. if ‘return\_overflowing\_token = True’ exist, return Error code.
Huggingface document say that
- **return\_overflowing\_tokens** ( `bool` , _optional_ , defaults to `False` ) — Whether or not to return overflowing token sequences. If a pair of sequences of input ids (or a batch of pairs) is provided with `truncation_strategy = longest_first` or `True` , an error is raised instead of returning overflowing tokens.
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**Author:**  [@cog](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Fu%2Fcog)%5C
**Post date:** [May 17, 2022, 6:45am UTC](/static-proxy?url=https%3A%2F%2Fdiscuss.huggingface.co%2Ft%2Fchanging-tokenizers-max-length-gets-weird-result%2F18029%2F4 "2022-05-17T06:45:41Z")
