Using and saving your test data

Where test-log records are saved

The clay test log uses browser-local storage (localStorage) on https://withcalculator.com. Its save action stores your entry in the current browser profile; it does not upload the record to an account or sync it between devices.

Use the same browser, profile, and site address to return to your records. Other people using that profile may be able to view them. Clearing site data can erase records; private-browsing storage is usually removed when the private session ends. If the tool warns that storage is unavailable, changes are held only for the current page session and can be lost when you leave or reload.

Root domain and clay subdomain are separate

Records saved on clay.withcalculator.com do not automatically transfer to withcalculator.com. Browsers keep those origins’ storage separate. The move between paths on withcalculator.com, such as /test-log/ and /clay/test-log/, keeps the same storage area and record key in the same browser profile.

If you have records on the old clay subdomain, export its CSV there, then bring the file into the root log’s CSV importer if it matches the accepted format below. Exporting alone does not populate the root log: you must preview and confirm the import. Old subdomain JSON files are not supported by the root log’s JSON restore.

Keep a JSON backup for exact recovery

In the test log, choose Download JSON backup under JSON backup & restore. Keep the file privately and download a fresh copy after important changes, before clearing browser data, or before importing or restoring another file. Each download is a snapshot, not a continuously updated backup.

To restore, first back up the current log and close other test-log tabs, especially older open copies. Select an unmodified JSON backup from this root log using Choose JSON backup to restore, choose Preview backup, review the totals and skips, then confirm. Restore accepts schema v1 backups up to 5 MB and 5,000 records per file. It adds new record IDs only; duplicate IDs are skipped and reported even when their contents differ. Existing records are never overwritten or deleted by restore.

JSON is preferred for preserving exact record identity and text. Its SHA-256 check detects accidental file changes; it is not encryption or proof of who created the file. Backup and restore are processed locally on your device; no file or measurements are uploaded.

Export CSV for spreadsheets or local import

Save your test entries, then choose Export CSV. The downloaded clay-test-log.csv includes saved measurements, notes, calculated shrinkage percentages, and a final Record ID column in newer exports. Keep an unchanged copy for import; spreadsheet editing, rounding, or reformatting can make a file invalid or change how records are recognized.

Import a CSV safely

1. Choose Download JSON backup first to protect the records already in the root log.
2. Close other test-log tabs, including older open copies.
3. Open Import CSV exports and select the file with Choose test-log CSV export.
4. Choose Preview CSV. Review the totals, proposed additions, and all skipped or invalid rows before continuing.
5. Confirm only when the preview is right. Import adds only new records; existing records are never overwritten or deleted.

CSV import is entirely local: the file and measurements are not uploaded. It accepts this tool’s older 12-column exports and newer exports with a final Record ID column. Use UTF-8 (an optional BOM is supported), comma-delimited CSV with the original headers in their exact order. Quoted fields, doubled quotes, and multiline notes are supported. Limits are 5 MB and 5,000 data rows, with no more than 5,000 records total in the log. Unrecognized or reordered headers and broken quoting reject the whole file; other malformed rows are skipped and explained by starting line number.

Duplicate or conflicting record IDs are skipped and reported, not used to update existing tests. For old CSV rows without IDs, duplicates are detected by an exact, full-field fingerprint of the body, label, date, unit, lengths, cone, and notes; spacing and units are not normalized. This cannot distinguish intentionally separate but identical tests. Legacy CSV also cannot always distinguish an intentionally typed leading apostrophe from an apostrophe added for spreadsheet formula safety. Prefer JSON backup and restore for exact identity and text recovery.

Deleting a record, choosing Clear all records, or clearing browser site data can remove tests from this browser. Download and safely keep a JSON backup before doing so; CSV is useful for spreadsheets and compatible imports, but is not an exact replacement for JSON.

Send measurements to the calculator

For a saved test with a fired length, Use in calculator passes the wet and fired measurements and their unit to the shrinkage calculator using temporary browser-local storage. The calculator reads and removes that transfer. It does not copy the dry length or firing notes, and it leaves the desired final size for you to set. This handoff needs browser storage to work.

Ordinary calculator inputs are not saved as test-log records. To keep a measurement history, enter and save it in the test log.

The printable card does not save entries

The printable test card holds typed entries only in the open page. It does not save them to the test log, transmit them, or automatically transfer them to the calculator. Leaving or reloading the page can lose the entries.

Use Print test card to print a paper copy or choose your browser’s Save as PDF option, if available. Check the print preview and keep that copy yourself. To compare the results in the log later, enter them there separately.

About these data notes

This page describes how the clay test log, calculator handoff, and printable card handle your entries. It is not a claim that the whole website uses no cookies, analytics, server logs, or third-party services.

For the calculation definitions and source references, read How our clay calculations work.

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