GPT-3.5 Token Counter

Count tokens for GPT-3.5 Turbo. Uses the real tiktoken WebAssembly with cl100k_base — the tokenizer GPT-3.5 and the original GPT-4 share. For migrating away from GPT-3.5, compare against the GPT-5 token counter or GPT-4o counter on the same text — newer models use o200k_base which is typically 5-15% more efficient.

How to use the GPT-3.5 Token Counter

Paste text. GPT-3.5 uses cl100k_base — a ~100K-token vocabulary. For the same English text, this tokenizer typically produces 5-15% more tokens than o200k_base (GPT-4o / GPT-5). For non-English, the gap can be larger.

Should you still use GPT-3.5?

By 2026, GPT-3.5 is rarely the right choice. GPT-4o Mini at $0.15 / $0.60 per million tokens is cheaper than GPT-3.5 ($0.50 / $1.50) AND substantially better. GPT-5 Nano at $0.05 / $0.40 is cheaper still. The only case for keeping GPT-3.5 is a long-running production workload where the output style is baked into downstream parsers and a model swap is more work than it's worth.