Convert NDJSON to Excel Online
Convert NDJSON files to Excel format directly in your browser. No upload required — your data never leaves your device.
About this conversion
This tool converts NDJSON files to Excel format directly in your browser — no account required, no file upload, no waiting for a server. It processes your data entirely within your browser using WebAssembly, so nothing ever leaves your device.
The tool preserves all columns and data types from your source file and writes a valid Excel file ready to download. Large files are handled efficiently using a vectorised columnar engine.
Frequently Asked Questions
What is Excel format?
Excel (XLSX) is Microsoft's spreadsheet format, widely used in business. It supports multiple sheets, formulas, and formatting.
Is my NDJSON data private?
Yes — completely. Your file is never uploaded to any server. All conversion happens inside your browser using WebAssembly — locally, with no upload. Once you close the tab, nothing is retained.
What is the maximum file size?
The free limit is 50 MB. For larger files, performance depends on your device's available memory — most modern machines can handle 500 MB to 1 GB comfortably.
What is the difference between NDJSON and Excel?
Both NDJSON and Excel are common data formats used in engineering and analytics workflows.
Related Tools
Coalesce Columns in Excel Files Online
Fill null values in Excel files from other columns — return the first non-null value across up to 8 columns in priority order. Add the result as a new column. Runs entirely in your browser.
Add UUID Column to Excel Files Online
Add a UUID column to Excel files directly in your browser. Generate random UUIDv4 or time-ordered UUIDv7 identifiers for every row. Choose the column name and position — no upload required.
Pad Column in Excel Files Online
Left-pad or right-pad a column in Excel files to a fixed width directly in your browser. Zero-pad numeric codes, pad product IDs to a fixed length, or right-pad text fields — no upload required.
Compute Percentiles for Excel Files Online
Compute percentiles, median, MAD, mode, and kurtosis for numeric columns in Excel files directly in your browser. Optionally group by a category column. Results download as CSV — no upload required.
Find Arg Max / Min in Excel Files Online
Find the value of one column at the row where another column is maximum or minimum in Excel files — directly in your browser. Optionally group by a category to get per-group results. No upload required.