d/d

Developer utility

Remove CSV Rows That Contain Empty Cells

Use this tool to clean a comma-separated CSV without sending the file to an application server. It keeps the first row as the header, then removes every later row with at least one empty or whitespace-only cell. You can process the same file with the JavaScript streaming version or the Go WebAssembly version, compare their timing in your browser, and download the cleaned CSV.

What it does

  • Read a local `.csv` file in chunks rather than submitting its contents through a form.
  • Preserve the first CSV record as a header and reject later rows containing any trimmed empty cell.
  • Process the file with JavaScript streaming or a Go WebAssembly module using a configurable worker count.
  • Show progress, processing logs, elapsed browser time, and retained-versus-original data-row counts for both implementations.
  • Download the cleaned result as a new UTF-8 CSV file with a `cleaned_` filename prefix in English.

How to use CSV Empty-Cell Row Cleaner

  1. Select a CSV file

    Choose or drag a `.csv` file into the uploader. The file remains available to the page as a local browser File object.

  2. Choose the comparison path

    For Go WebAssembly, set the goroutine worker count after the module loads; for JavaScript, use the serial streaming panel.

  3. Process the rows

    Start either implementation and follow its progress log, elapsed time, and retained-row count.

  4. Compare carefully

    Run both implementations if the comparison is useful. The timing only describes this browser, device, file, and worker setting; it is not a universal benchmark.

  5. Download the cleaned file

    Use Download Result in the completed panel to save the generated CSV to your device.

Formats, compatibility, and limits

Inputs

  • One local file selected through an input restricted to the `.csv` extension.
  • Comma-separated rows whose first record is treated as the header.
  • A Go worker-count setting from 1 up to the browser-reported logical concurrency limit.

Outputs

  • A cleaned CSV string and downloadable UTF-8 `.csv` file.
  • Counts for original data rows and retained data rows; the header is not counted as a data row.
  • Separate progress logs and elapsed browser timings for the Go WebAssembly and JavaScript implementations.

Compatibility

  • Requires WebAssembly for the Go path; the JavaScript path also depends on modern File streaming APIs.
  • Uses UTF-8 decoding and a comma delimiter with no delimiter or encoding selector.
  • Processing capacity depends on available browser memory, file size, device performance, and the selected Go worker count.

Known limits

  • The cleaner removes a whole data row when any cell is empty after trimming; it does not merely remove fully blank lines.
  • Only comma-separated input is supported. Semicolon, tab, and custom delimiters are not detected.
  • The JavaScript parser handles quoted commas with a compact expression but is not a complete RFC 4180 parser; multiline quoted fields are unsafe.
  • The two implementations use different parsers, so malformed or edge-case CSV can produce different results.
  • Displayed timings are not controlled benchmarks and should not be generalized to other browsers, devices, files, or worker settings.
  • The entire cleaned output is accumulated in browser memory before download.

Privacy and processing

  • The selected file is read and cleaned inside the browser; its CSV contents are not uploaded by the tool.
  • The page fetches its own Go WebAssembly program, but the selected CSV remains a local File object supplied directly to the JavaScript or WebAssembly processor.
  • Input and output are not persisted to local storage or IndexedDB; refreshing clears the current results.

How the JavaScript and Go WebAssembly cleaners differ

Both cleaners keep the first row and retain only later rows in which every cell contains non-whitespace text. The JavaScript version reads the File stream incrementally, decodes UTF-8 chunks, and uses a quote-aware comma split. The Go module reads five-megabyte slices, sends newline-aligned jobs to goroutine workers, parses them with Go’s `encoding/csv`, restores their original order, and assembles the output. These paths use different parsers and scheduling models, so the timing is an experiment, not proof that one language is always faster.

Questions about CSV Empty-Cell Row Cleaner

Does this remove only completely blank rows?

No. A data row is removed when any of its cells is empty or contains only whitespace. The first record is treated as the header and preserved separately.

Is my CSV uploaded?

The file is read through browser File APIs and processed on the page. The tool downloads its own WebAssembly module for the Go option but does not send the selected CSV contents to an application server.

Does it support semicolon-separated or tab-separated files?

No. The current implementations assume commas and provide no delimiter selector or automatic delimiter detection.

Why can the Go and JavaScript results or times differ?

The two versions use different parsers and scheduling strategies. Browser load, file shape, worker count, malformed records, and multiline quoted fields can change the timing or the output at the edges.