CSVUndo vs CSVFix, side by side
| Feature | CSVUndo | CSVFix |
|---|---|---|
| Price | Free, no tiers | Free up to 50 KB, then $4.99 (1 MB) / $9.99 (5 MB), per CSVFix’s published pricing page as of August 2026 |
| File-size limit | No paid limit — up to 250 MB on a capable Chrome/Edge machine; less in Safari, Firefox, or on lower-memory devices | 50 KB free; 5 MB max on the paid plan |
| Where your file is processed | In your browser — never uploaded | On CSVFix servers (per its FAQ, files are "kept in memory during processing and automatically deleted") |
| Works offline after load | Yes | No |
| Signup required | No | No |
| Fix scientific-notation barcodes | Yes, dedicated tool | Not on its published transform list when we checked |
| Restore leading zeros | Yes, dedicated tool | Not on its published transform list when we checked |
| Fix mojibake / encoding | Yes | Yes (Fix Encoding) |
| General transforms (arithmetic, phone/address/company standardise, generate SKUs) | Not the focus | Yes — broader toolkit |
| Merge / split / join files | Yes | Split and merge columns; whole-file merge not on its published list when we checked |
Comparison compiled on 12 August 2026 from CSVFix’s own public pricing page and FAQ, both linked above; every “not listed” cell means we could not find it published on that date, not that it cannot be done. A competitor’s site changes without notice, so check it yourself before relying on any row here, and tell us if one is out of date — we will correct it. CSVFix is a trademark of its owner; this page is an independent comparison, not affiliated with CSVFix.
Why the 50 KB limit matters more than it looks
50 KB is only a few hundred rows of typical product or contact data. Most real business exports — a Shopify catalogue, a customer list, a month of transactions — sail past that in the first screen, which pushes you onto a paid tier just to process one file. CSVUndo has no paid size gate: because the repair runs in your own browser, there is no server bill to meter, so a 5 MB or 50 MB file costs exactly the same as a tiny one — nothing. The only ceiling is your own browser’s memory: up to 250 MB on a capable Chrome or Edge machine; Safari, Firefox and lower-memory devices get a lower one.
Why "processed on our servers" matters for business data
Server-based tools have to receive your file to work on it. CSVFix's FAQ is upfront that files are "kept in memory during processing and automatically deleted once the transformation is complete" — reasonable, but it still means your customer list, prices or barcodes are transmitted off your machine. If you handle data that shouldn't leave the building — anything customer-identifying, financial, or under a data-processing agreement — that upload is the part your policy cares about. CSVUndo never uploads the file in the first place: you can pull your network cable after the page loads and every tool still works — three ways to verify the no-upload claim.
When CSVFix is the better pick
To be fair: if you need general-purpose data wrangling — arithmetic between columns, standardising phone numbers or company names, generating SKUs, or bulk text transforms — CSVFix offers a broader menu than we do, and the paid tiers are inexpensive. CSVUndo deliberately stays narrow: it is the tool for when Excel has broken a CSV and you need it valid again, free, and private. Many people use both.
No paid size limit, no signup, nothing uploaded. Start on the homepage or jump to the exact fix you need.
Open CSVUndoThe CSVUndo repair tools
Match the damage to the tool: scientific-notation barcodes, lost leading zeros, broken characters (mojibake), encoding checker, delimiter converter, duplicate/blank-row cleaner, or a broken Shopify product CSV. See them all on the tools page, or read the guides for the background.
Frequently asked questions
Is there a free CSVFix alternative with no paid size limit?
Yes — CSVUndo is free with no paid size gate. CSVFix's free plan caps files at 50 KB and charges $4.99 for 1 MB or $9.99 for 5 MB as of August 2026. CSVUndo handles files up to about 250 MB on a capable Chrome or Edge machine; Safari, Firefox and lower-memory devices get a lower ceiling. That limit is your own browser's memory rather than a paywall — because nothing is uploaded, there is no bandwidth for anyone to meter.
Does CSVUndo upload my file like server-based tools do?
No. Your file is processed locally in your browser tab and never transmitted anywhere. CSVFix's FAQ notes that files are "kept in memory during processing and automatically deleted" — i.e. sent to its servers to be processed. With CSVUndo there is nothing to delete, because nothing is ever uploaded.
What does CSVFix do that CSVUndo does not?
CSVFix has a broader set of general data-prep transforms (arithmetic between columns, phone/address standardisation, SKU generation and more). CSVUndo is focused on repairing Excel-damaged CSVs — scientific notation, leading zeros, mojibake, encoding and delimiters — plus merge, split and join. Pick CSVUndo when the file is broken.