Context Window Fit Checker
Tokenize a prompt stack and inspect editable context-window fit bars with output reserve.
Enabling local controls…
Results
Review the inputs, then run to create a readable result and complete export. Editing cancels active work and clears stale results.
Formula, sources and limits
Used = encoded system + docs + history + explicit wrapper overhead + output reserve. Each bucket is encoded separately. Provider formats and separate maximum-output limits must be verified. Rates, limits, subscriptions and latency defaults are illustrative custom assumptions, not current vendor quotes or benchmarks. Check official sources and replace them. Each text field ≤32,768 UTF-16 units, total input ≤128 KiB, output ≤1 MiB; local job timeout 30s.
Methodology checked:
How to use this tool
Load the safe sample, review every labeled assumption, then run. Edit any field to clear old results. Copy or download the complete result. Processing stays in this tab.
When not to use it
Used = encoded system + docs + history + explicit wrapper overhead + output reserve. Each bucket is encoded separately. Provider formats and separate maximum-output limits must be verified. Rates, limits, subscriptions and latency defaults are illustrative custom assumptions, not current vendor quotes or benchmarks. Check official sources and replace them. Each text field ≤32,768 UTF-16 units, total input ≤128 KiB, output ≤1 MiB; local job timeout 30s.