AnyTool
Your files never leave your device. All processing happens locally in your browser.

How do I find row-level errors in a CSV before importing?

Paste your CSV into AnyTool's Import Error Review Sheet. It infers each column's type, then scans every row for import problems — missing values in otherwise-populated columns, cells that don't match the column type (bad emails, invalid dates, non-numeric numbers), and over-long values — and produces a row-level error sheet you can filter by severity and export. Dates are validated with a proper UTC parser, not the browser's locale guesser. Everything runs in your browser — nothing is uploaded.

  • Per-row issues: missing values, type mismatches, bad email/date, over-long
  • Column-type-aware checks; errors vs warnings
  • Filter by severity; export an error sheet or the clean rows
  • 100% in your browser — no upload, no signup

What is

Import error review

Import error review is the process of scanning a data file row by row before importing it, surfacing the specific cells that will fail or look wrong — missing required values, type mismatches, malformed emails or dates, and out-of-range values — so they can be fixed in advance. Client-side review does this in the browser without uploading the data.

File Tools

Related terms

data validationrow-level errorsCSV QAtype mismatchdata cleansing

How to Review CSV Import Errors

Scan a CSV for row-level errors and export an error sheet, in your browser.

20 secWeb browser
  1. 1

    Paste CSV

    Paste your data with a header row. The scan runs live.

  2. 2

    Review issues

    Filter by error or warning and inspect each flagged cell with its message.

  3. 3

    Export

    Download the error sheet or the clean rows — nothing is uploaded.

Result: A row-level error sheet and a clean-rows export

Frequently Asked Questions

Missing values, cells that don't match the column's type, malformed emails and dates, and over-long values.

It infers each column's dominant type and flags non-conforming cells as errors, with whitespace and missing-value issues flagged as warnings.

With a deterministic UTC date parser, not the browser's locale-dependent Date(), so results are consistent.

That avoids the silent mis-parsing of ambiguous dates that plagues naive validators.

No — every check runs locally in your browser.

You can export an error sheet or just the clean rows without your data ever leaving the device.

Detailed Explanation

Methodology

How the Import Error Review Sheet Works

AnyTool reviews a CSV row by row entirely in the browser. The file is parsed with PapaParse and rectangularised to the header width, then each column's dominant type is inferred from its non-empty cells. Every row is scanned for problems: a cell that does not match its column type is an error (emails checked structurally, dates validated with a deterministic UTC parser rather than the browser's locale guesser, numbers parsed locale-aware), while a missing value in an otherwise-populated column, stray whitespace, or an over-long value is a warning. A row with any error is not clean; warning-only rows are counted separately. The result is a row-level error sheet you can filter by severity and export, plus a clean-rows export. Nothing is uploaded.

  • Runs client-side — the file is never uploaded
  • Column-type inference drives type-aware row checks
  • UTC date validation, structural email checks, locale-aware numbers
  • Errors vs warnings; clean rows tracked separately
  • Export the error sheet or just the clean rows
  • No CDN, no backend, no row cap
Privacy & Security

Privacy vs Upload-based Importers

Import platforms such as Flatfile and Dromo show a review screen after uploading your data to their servers. AnyTool produces the same kind of row-level error review locally, so the file never leaves the browser, there is no row cap, and it works offline after first load — with deterministic date handling that avoids locale-dependent mis-parsing.

Import error review: AnyTool vs typical importers
CapabilityAnyToolTypical importers
Data handlingIn your browserUploaded to a server
Date validationDeterministic UTCOften locale Date()
SeverityErrors + warningsVaries
CostFree, no signupAccount / paid
ExportError sheet + clean rowsVaries

AnyTool is a privacy-first client-side error reviewer — rows are checked locally and never uploaded.