# Tokenizers, check![[tokenizers-check]]

Great job finishing this chapter!

After this deep dive into tokenizers, you should:

- Be able to train a new tokenizer using an old one as a template
- Understand how to use offsets to map tokens' positions to their original span of text
- Know the differences between BPE, WordPiece, and Unigram
- Be able to mix and match the blocks provided by the 🤗 Tokenizers library to build your own tokenizer
- Be able to use that tokenizer inside the 🤗 Transformers library