When you type a word in Slack for Desktop (Mac or Win) and it is wrongly spelled it is highlighted. I want to add a word which is highlighted in Slack as wrong (Salesforce it is) and make Slack understand that the word is spelled correctly. Is there a way to do this?

  • 2
    Am I correct to assume that you are using the Slack desktop client on Windows? May 17, 2019 at 14:05
  • Also broken on Mac, even for words already in the custom dictionary. Feb 28, 2020 at 16:18

2 Answers 2


On the mobile version (Android 9) Slack pulls from phone's dictionary, including any words you have added. "Salesforce" (and all major brand names) are already included, but after adding "Salesfarce" to the android dictionary Slack did not error highlight that word.

On the windows slack client the system dictionary found at %AppData%\Microsoft\Spelling\en-us\default.dic is not used and instead slack includes a custom .bdic (binary dict file) at %AppData%\Local\Packages\%someHash%.Slack_%someHash%\LocalCache\Roaming\Slack\dictionaries.

THIS stackoverflow post details how to merge the bdict with a custom word list. In short the only available tool (at time of writing) to do this merge is Chromium.

  • For the macOS users, the related dictionary file is located at ~/Library/Spelling/LocalDictionary. So you can add/remove/edit the words there. Feb 3, 2022 at 17:22

These days the Windows Slack client is using the system dictionary found at %AppData%\Microsoft\Spelling\en-us\default.dic

  • 1
    I just tested it by telling Slack that I want to add a word (right-click on red-squiggle-underlined word), and it appears in that file
    – tbc0
    Feb 11, 2022 at 18:07

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