When a checksum is invalid, warn the user that the phrase is not something generated by your app, and ask if they would like to use it anyway. This way, your app only needs to hold the wordlists for your supported languages, but you can recover phrases made by other apps in other languages.
However, there should be other checks in place, such as checking to make sure the user is inputting 12 words or more separated by a space. ie. `phrase.trim().split(/\s+/g).length >= 12`
Browserify/Webpack bundles can get very large if you include all the wordlists, so you can now exclude wordlists to make your bundle lighter.
For example, if we want to exclude all wordlists besides chinese_simplified, you could build using the browserify command below.
```bash
$ browserify -r bip39 -s bip39 \
--exclude=./wordlists/english.json \
--exclude=./wordlists/japanese.json \
--exclude=./wordlists/spanish.json \
--exclude=./wordlists/italian.json \
--exclude=./wordlists/french.json \
--exclude=./wordlists/korean.json \
--exclude=./wordlists/chinese_traditional.json \
> bip39.browser.js
```
This will create a bundle that only contains the chinese_simplified wordlist, and it will be the default wordlist for all calls without explicit wordlists.
For a list of supported wordlists check the wordlists folder. The name of the json file (minus the extension) is the name of the key to access the wordlist.
You can also change the default wordlist at runtime if you dislike the wordlist you were given as default.