Methodology

Last reviewed by the tokenwatch team on 2026-06-29.

tokenwatch records the price of large language model APIs once per day and keeps the full history, so you can see how each model's cost changes over time rather than just today's number.

Where the data comes from

Prices are collected from public, openly published provider pricing aggregated byOpenRouter's models API. Each day we take one snapshot and store it verbatim.

How prices are normalized

• Source prices are given per token; we multiply by 1,000,000 and show USD per 1M tokens.
• Input (prompt) and output (completion) prices are tracked separately, plus cache read/write where published.
• Free models and entries without a paid input/output price are excluded from price history.

History

We currently hold 1 daily snapshot (latest:2026-06-29). A new snapshot is added automatically every day, so trend lines lengthen on their own — historical data cannot be back-filled, which is exactly why we started recording.

Corrections

Provider pricing can change without notice and aggregator data can lag. If you spot a figure that looks wrong, the snapshot date on each page tells you exactly when it was recorded.