Editing a large XML file in Excel: the “sample first” method

What ExcelifyXML accepts today

• Transformation (XML → CSV): up to 4 MB on the free plan, up to 30 MB on the VIP plan (secure direct upload, nothing retained).
• Reconstruction (CSV → XML): free and credit-less for everyone. It accepts a .excelify.zip bundle up to 4 MB — roughly 30 MB of XML once rebuilt, since the bundle is compressed.
• The rebuilt XML has no size ceiling: it is streamed back to you whatever its length.

The key idea: structure does not depend on volume

When ExcelifyXML transforms an XML file, it produces two files: data.csv (your data) and skeleton.json, the structure manifest — tag order, attributes, namespaces, how each row is rebuilt. That manifest describes the SHAPE of your data, not how much of it there is.

The practical consequence: a 200-product sample with exactly the same structure as your 50,000-product catalog yields exactly the same manifest. So you can transform the small file, then rebuild the big one.

The “sample first” workflow in 4 steps

1. Extract a representative sample from your large XML: keep the header, the root tag, and a few dozen or hundred repeated elements (products, entries, URLs…) that cover every field in use. Any text editor will do — or ask your PIM/CMS for it.
2. Transform that sample (a few KB to a few MB) on the Upload page. You get the .excelify.zip bundle: data.csv + skeleton.json.
3. Open data.csv in Excel, Google Sheets or LibreOffice and replace its contents with the full dataset, keeping the same columns (same headers, same order). You can also generate those rows from a database or another spreadsheet: only the columns matter.
4. On the Reconstruction page, choose “Separate files” and drop your complete data.csv together with the original skeleton.json — no archive handling: the site compresses and sends both files for you. You get your complete XML, with the exact structure of the original. (If you prefer, you can also re-zip the two files yourself and drop the bundle.)

What you gain

• A single credit consumed, even for a 30 MB catalog: transforming the sample is enough, reconstruction is unlimited and free.
• A lightweight working file in Excel: you edit the volume in the spreadsheet, not in a 30 MB XML that makes your editor crawl.
• A repeatable flow: keep skeleton.json aside and regenerate your XML as often as you like from any CSV export with the same structure.

Pitfalls to avoid

• The sample must contain ALL the fields that exist in the large file: a field missing from the sample will be missing from the manifest, hence from the rebuilt XML.
• Keep the column headers intact (column names are the link between the CSV and the structure). Adding rows is free; renaming a column breaks the mapping.
• If your spreadsheet is in French, it saves CSV with semicolons: that is expected, ExcelifyXML detects the delimiter automatically.

Privacy

Your files are never retained: processed in memory on European Union servers, then deleted immediately. Large files transit for a few seconds through a private, encrypted space, wiped as soon as processing ends. No metadata is kept.