Who it is for

Anyone with big, messy spreadsheets

If you keep hitting the same wall, a file that will not open, a .csv.gz you have to unpack first, columns that arrive in a different order every month, BigXL is built for exactly that. It opens spreadsheets of any size, tidies the messy parts, and splits or merges files from a menu. No formulas, no code, and nothing is uploaded.

The file that will not open

Some files are simply larger than a spreadsheet grid is built to hold. BigXL opens CSV, TSV, TXT, PSV and DAT, compressed .gz and .zst, Parquet, and Excel workbooks, at any size, with no row limit. Files of 50 GB have been tested.

It streams from disk rather than loading everything into memory, so you start scrolling within seconds while indexing continues in the background. Sorting, filtering, summaries, charts and pivots are all free.

The export that arrives dirty

Real exports are rarely tidy, and the same handful of problems come back every time. The Pro cleaning tools handle them from a menu, with a preview before anything is applied:

• Long numbers such as order IDs, barcodes and account numbers kept whole, rather than turning into 8.43E+12 or losing their last digits
• Leading zeros preserved instead of being stripped off
• Mixed date formats standardised to one pattern, with genuinely ambiguous dates refused rather than guessed
• Currency columns stripped of symbols, thousands separators and brackets for negatives, so the totals add up
• Stray text in numeric columns grouped together so you decide what happens to each bad value
• Whitespace and inconsistent casing trimmed and re-cased in one pass

Rows that cannot be read at all go to a rejects panel with the reason for each, so nothing disappears quietly.

Splitting, merging and deduplicating

Combining files by copy and paste is where quiet errors creep in. If one file has its columns in a different order, values land in the wrong place and nothing warns you. BigXL merges on the header name, keeps columns that only some files have, and shows you the result first.

Removing duplicates works on the columns you choose, across the whole file, and counts what it will remove before it removes anything. Splitting a file into parts writes the header into every part, so the later pieces keep their column names.

Often the honest answer is that you do not need to split at all. Splitting is usually a workaround for a row limit, and there is not one here.

The same job next month

When the same export arrives every month, the cleanup repeats with it. Record the steps once as a recipe and replay it on the new file. If a header has been renamed since last time, a recipe that matches on column name will flag it rather than quietly applying the step to the wrong column.

Nothing leaves your computer

BigXL makes no automatic network requests. Your files are never uploaded, there is no account to create, and there is no telemetry. Bix, the plain English assistant, runs on your own processor, so you can ask questions about a file without sending it to a cloud service. It all works the same with the network switched off.

Common questions

Can I open a .csv.gz file without unzipping it first?

Yes. BigXL reads gzip and zstd compressed files directly, so you skip the extraction step and the temporary disk space it needs. A 1 GB compressed file often unpacks to 8 GB or more, and you do not have to find room for it. Reading compressed files is free.

What happens when a file has broken or ragged rows?

They are set aside and explained rather than silently dropped. BigXL collects unreadable lines into a rejects panel with the reason for each, such as an unclosed quote or an uneven column count, so you can decide what to do about them.

How do I merge files whose columns do not match?

BigXL merges on the header name rather than the column position, so a renamed or reordered header does not shift values into the wrong column. Columns that appear in only some of the files are kept, with blanks where a file did not have them, and you see the result before anything is written.

Do I have to redo the same cleanup every month?

No. Record the steps once as a recipe and replay it on next month's file. Recipes are a Pro feature, and the Enterprise tier can run one across a whole folder at once.

Is it free to just open and look at a file?

Yes, with no row limit and no account. Opening, scrolling, sorting, filtering, summary statistics, charts, pivot tables and CSV export are free forever. The paid tiers add the cleaning transforms, the plain English assistant and the privacy tools.