Is my data really private?

Yes. All substitution runs in your browser tab. No data is sent to any server. Session history lives only in localStorage. Shareable URLs encode your data as a base64 string in the URL — no server stores it. Verify by opening your browser's Network tab (F12 → Network) and observing zero outbound requests when you click "Process All".

How does batch pagination work?

Set a batch size (10, 25, 50, 100, 250, or 500) using the Batch Size control above the Process button. "Process All" runs the first batch starting from row 1. A "Process Next N" button then appears — click it to advance through the dataset in controlled chunks. This is useful for spot-checking results before committing to a full large-dataset run.

How do I save a custom template?

Click the "Save" button next to the template editor header. Give your template a name and optional description, then click "Save Template". Your custom templates appear in the Template Library under the "My Templates" tab. They are stored in your browser's localStorage and persist across sessions. You can edit or delete them at any time.

Diff view shows a side-by-side comparison of the original template (left) and the substituted result (right). {{variable}} placeholders are highlighted in amber on both sides — the left shows the placeholder name, the right shows the substituted value. This makes it easy to audit substitution accuracy at a glance, especially for multi-variable CSV templates.

How does multi-column CSV substitution work?

Upload or paste a CSV where the first row contains column headers (e.g., product_name, category, price). The tool automatically maps each {{column_name}} placeholder in your template to the corresponding column value for each row. Column names are case-insensitive and spaces are converted to underscores.

How accurate is the token estimator?

The estimator uses the ~4 characters per token heuristic, accurate to within 10–15% for standard English text. For non-English content, code, or heavily punctuated text, actual token counts may differ. For precise counts, use the tokenizer provided by your target model's API.

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