Compare, split, merge and
anonymize files in your browser
Four browser-only tools for messy data: find missing rows, split a large export into smaller files, merge sources into one, and anonymize PII before sharing it with a teammate or an AI assistant. Nothing leaves your tab.
No upload. The anonymization mapping stays on your machine. Reverse it any time.
Free account → 3× higher daily limits + payment history.
Why MessyMatch
Four tools, one browser tab, your data stays put
Browser-only by design
Parsing, comparison, splitting, merging and anonymization run in a Web Worker inside your browser. No upload, no cloud processing. Just JavaScript on your tab against your file.
Reversible anonymization
Hash, redact, faker and pseudonymize methods, with a separate mapping file you control. Send anonymized data to ChatGPT, get the answer back, then translate tokens to real values locally. No second exposure.
Compare/Split/Merge/Anonymize in one place
Stop juggling three tools and a privacy filter. The same browser tab does the four jobs that come up in messy-data work, with one consistent interface and one pricing table.
Your files should stay yours.
MessyMatch processes everything in your browser using a Web Worker. Your file contents are processed in your browser via a Web Worker and are not transmitted to our servers, because we operate server endpoints for auth, payments and rate limits, but none of them receive your file contents. If a future feature ever needs server processing, we will tell you clearly before uploading anything.
Use cases
Four jobs the same browser tab handles
- Compare customer lists across systems
- Match invoices in accounting exports
- Reconcile shipping vs delivery logs
- Cross-check leads from two campaigns
- Find missing SKUs between catalogs
- Detect duplicate emails before sending
- Cut a 200 MB CSV for a 50 MB import
- Break a SQL dump into runnable chunks
- Reorder a workbook into one file per country
- Distribute leads as N files for N reps
- Cut an Excel export under an upload size cap
- Prepare partials for a batch-import script
- Recombine monthly exports into one clean file
- Join partials produced earlier by Split
- Consolidate reports from different teams
- Append batches with the same schema
- Add a source_file column to audit row origin
- Drop exact duplicate rows across files
- Strip PII before pasting customer data into ChatGPT or Claude
- Pseudonymize names, emails and DNIs with a reversible mapping
- Hash IDs so joins work without exposing identities
- Mask Excel exports before sharing with contractors
- GDPR Article 4(5) pseudonymization for compliance audits
- Reverse the anonymization later with the mapping file you saved
Pricing
Small Compare operations are free.
Compare and Merge follow the same tiers: free up to 2,000 rows, then pay-as-you-go ($3 / $7 / $15 / $29 by row count). Compare is priced by the largest file; Merge by total rows across all files. Split is always free with a daily limit shared with free Merges: 1 fileutil operation every 24 hours without an account, 5 per day with a free account.
| Largest file | Price |
|---|---|
| Up to 2,000 rows | Free |
| Up to 25,000 rows | $3 |
| Up to 100,000 rows | $7 |
| Up to 500,000 rows | $15 |
| Up to 1,000,000 rows | $29 |
One-off payment per operation, processed by Stripe. No subscriptions, no hidden fees.
Try it on real data
Load a sample or drop your own file
Samples cover all four tools: compare reconciliations, split imports, merge batches, and PII-loaded files ready to anonymize (and a reverse demo too). No account needed.
Two customer CSV exports with accents, casing differences and missing rows.
ERP and shop catalogs with SKU separators, missing items and changed prices.
Reconcile invoices between accounting and bank with leading zeros and changed amounts.
A 10,500-row customer CSV ready to split into 2,000-row partials.
A simple SQL dump with ~500 INSERT rows to split into import-ready chunks.
Three monthly customer exports with the same schema, ready to merge into one clean file.
Two product CSVs with different columns. Perfect to demo the combined schema option.
20 customers with names, emails, Spanish DNIs and phones. Auto-detection pre-selects the right method per column.
15 employees with valid Spanish IBANs and salaries. Numeric columns pass through; IBAN gets pseudonymized.
30 orders where only the email column is PII. Reversible pseudonymization keeps analytics joinable.
Anonymized 10-row CSV plus the mapping file. Drop both into the reverse tool to recover originals.
A simulated ChatGPT response with anonymized tokens plus the matching mapping. Try paste-text mode.
FAQ
Compare, split, merge & anonymize. Answered
Do I need an account?+
No. Open the page, drop a file, get the result. There is no signup, no email verification, no cookie banner.
Are my files uploaded somewhere?+
No. Parsing, comparison and splitting happen entirely in your browser using a Web Worker. Our servers do not have an endpoint that ingests file contents.
What file types are supported?+
Compare and Merge support CSV, TSV, TXT and XLSX. Compare also accepts pasted text. Split additionally handles simple SQL dumps. Almost matches are suggestions. Review before trusting.
How big can my files be?+
CSV and TXT files with several million rows work on a modern computer. XLSX is limited by what the format reader can hold in memory. For very large spreadsheets, export to CSV first.
Can I split a SQL dump?+
Yes. The split tool parses the dump, preserves the preamble (CREATE TABLE, SET, LOCK) in every partial, and reparts the INSERT statements.
What is Merge for?+
Merge combines two or more compatible files into one clean output. It can keep one header, match columns by name, remove exact duplicate rows and add a source_file column. It is not a SQL join.
Can I use it for sensitive data?+
Yes, with the caveats that apply to anything in a browser tab. Files do not leave your machine. We do not log file contents. We collect anonymous usage events. Never the data itself.
Is anonymization run in my browser too?+
Yes. The anonymize and reverse engines run in a Web Worker inside your browser, same as Compare/Split/Merge. File contents never reach our servers. We only store the row counts and bytes needed to enforce the paid tier.
What methods can I pick for each column?+
Four: hash (one-way SHA-256), redact (placeholder), faker (synthetic but realistic. Valid Spanish DNIs, IBANs, emails) and pseudonymize (reversible tokens like EMAIL_0001 with a separate mapping file).
Can I reverse the anonymization later?+
Yes if you used pseudonymize or reversible faker. Both produce a mapping file. Drop the anonymized file and the mapping into the reverse tool to get the originals back, locally, free, no rate limit.
Is anonymize free?+
Free up to 2,000 rows, same tier table as Compare and Merge above that: $3 / $7 / $15 / $29 per operation. Reverse is always free.