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Metrillix Migrate / Local spreadsheet tools / Beta

Stop cleaning the same spreadsheets every month.

Upload your CSV or Excel file, clean inconsistent data, preview every change, and save your cleaning rules to reuse next time.

Clean a Spreadsheet — Free See How It Works ↓

Your spreadsheet is processed locally in your browser. File contents are not uploaded to our servers.

01 / A small monthly reportSynthetic data
Before: extra spaces and a repeated invoice
InvoiceCustomer
INV-01 Ana João
INV-01 Ana João
INV-02 අමාලි
Trim spacesThen compare invoice keys
3 input rows. Two explicit rules.

This preview uses the same transformation engine as the workspace. Invoice-only deduplication is suitable for this synthetic example; choose keys for your own record structure.

CSV & XLSX inProtected CSV outNo account requiredNo AI processing
The tool bench / 03 available

Choose your next step.

Clean / Available now

Metrillix Migrate

Clean, prepare and migrate CSV/XLSX datasets with reusable recipes.

Open tool Convert / Available now

Metrillix Convert

Convert between CSV, Excel, JSON and TSV, locally in your browser.

Open tool Merge / Available now

Metrillix Merge

Append datasets, join tables and combine Excel sheets without code.

Open tool
A small routine, made repeatable

One file today.
A head start next month.

  1. 01

    Upload

    Choose a file or the synthetic sample. Confirm headers and inspect the first records.

  2. 02

    Clean

    Add explicit rules, choose comparison keys and review changed cells and removed rows.

  3. 03

    Repeat

    Download the CSV. Save the recipe, then apply it to the next compatible report.

The working set

Useful operations.
Visible decisions.

01

Clean the details

Trim spaces, normalize case and remove selected literal characters. Unicode stays text.

02

Choose your duplicate keys

Compare whole rows or selected columns. Keep first or last, then inspect removed records.

03

Make missing values explicit

Choose null markers and replacements. Missing cells do not silently delete records.

04

Put dates and columns in order

Choose a source date format, rename output fields, reorder or remove columns. Invalid dates stay flagged.

The part worth keeping

Keep the recipe.
Reuse the decisions.

Rules run in a deliberate order. Reordered columns are matched by name; renamed or missing fields get a review checkpoint. No fuzzy guesses are applied to your file.

A practical guide to recurring cleanup →
Monthly preparation / schema v1
  1. 01 Trim customer-name whitespace
  2. 02 Compare chosen invoice keys
  3. 03 Normalize explicitly formatted dates

Save locally. Export JSON. Review again next month.

Try month one →Inspect month two →
Designed with boundaries

Local. Bounded.
Under your control.

Input
UTF-8 CSV and XLSX; choose a worksheet.
Limits
15 MiB · 20,000 rows · 100 columns · 250,000 cells. Text and archive limits also apply.
Output
CSV with formula protection; JSON recipes and transformation reports. No XLSX export.
Storage
Files remain in browser memory. Only recipes you save are kept locally. Recipe/report settings can still be sensitive.

XLSX formatting, macros and computed formulas are not reproduced. No email/phone validation, workbook merging or unattended automation. Review outputs before importing them elsewhere.

Read the CSV preparation guide →
Before you begin

A few useful answers.

Do I need an account?

No. Import, clean, export and save a recipe locally without registration. The controlled beta is free to try. Future paid capabilities are research ideas, not available plans.

Where does my file go?

Spreadsheet processing happens in browser memory. The Migrate workflow does not upload file contents. An explicitly saved recipe stays in local browser storage; it can contain column names and replacement settings.

What does a recipe remember?

The ordered rules and their settings, including expected column names. It does not store imported rows, run on a schedule or sync between devices. Export the recipe JSON for a portable backup.

Will next month’s column order break it?

Reordered columns are matched by normalized header names. Renamed fields need explicit mapping. Extra columns require review, and missing required columns block execution. Header matching does not verify business meaning.

Which files and browsers can I use?

UTF-8 CSV and XLSX. The beta caps files at 15 MiB, 20,000 rows, 100 columns and 250,000 cells. Additional text/archive limits apply. Local Windows tests cover Edge, Chrome for Testing (Chromium), Firefox and Playwright WebKit. Stable Chrome, Apple Safari and actual mobile devices have not been separately verified.

Can I download Excel files or merge workbooks?

Export is CSV, with optional JSON recipe and report downloads. XLSX export, workbook merging, file-to-file comparison and CRM-specific validation are not available.

Are formulas and dates calculated automatically?

Formulas are never evaluated. Dates need an explicitly selected source format. Invalid values are preserved and flagged. XLSX formatting and calculated formula results are not reproduced.

Why does a negative number have an apostrophe in the CSV?

Formula-like text, including negative values, is apostrophe-prefixed on export to reduce spreadsheet formula-injection risk. This can affect downstream numeric typing. Test a small export with your destination system.

A cleaner start for the next report

Do the cleanup.
Keep the instructions.

Start with a sample →