Examples of weird GPT-4 behavior for the string " davidjl". GPT-4, when told to repeat or otherwise process the string “ davidjl” (note the leading space character), treats it as “jndl” or “jspb” or “JDL” instead. It turns out “ davidjl” has its own single token in the tokenizer: token ID 23282, presumably dating back to the GPT-2 days.
Riley Goodside refers to these as “glitch tokens”.
This token might refer to Reddit user davidjl123 who ranks top of the league for the old /r/counting subreddit, with 163,477 posts there which presumably ended up in older training data.
Recent articles
- My Lethal Trifecta talk at the Bay Area AI Security Meetup - 9th August 2025
- The surprise deprecation of GPT-4o for ChatGPT consumers - 8th August 2025
- GPT-5: Key characteristics, pricing and model card - 7th August 2025