Clean — by Similarity API

Fuzzy match two CSV files
in seconds

Find rows that refer to the same person, company, or product across two files — even when spelling, casing, or formatting differs.

Drop file or browse

CSV, XLSX, or XLS · up to 10 MB

Drop file or browse

CSV, XLSX, or XLS · up to 10 MB

Catches name variants VLOOKUP misses — Acme Inc. ↔ ACME, Incorporated

How It Works

How to fuzzy match two CSV files in 4 steps

Step 1

Upload

Drop your two CSV or Excel files. No signup, no install, no data stored.

Step 2

Pick match columns

Clean recommends which columns to match on — one column or several — and a similarity threshold. You can override it.

Step 3

Review

See every matched pair with a similarity score, plus the rows in each file that did not match anything.

Step 4

Download

Get the matched pairs as a single file, with scores and all the original columns.

FUZZY MATCHING ACROSS TWO FILES

Find the same person, company, or product across two messy files.

Fuzzy match two CSV files

Upload two files. Clean finds rows that refer to the same thing even when spelling, casing, abbreviations, or punctuation differ — and ranks every match by similarity score.

Catches name variants VLOOKUP misses — Acme Inc. ↔ ACME, Incorporated
Match on one column or several (company + contact, name + email)
Every match comes with a similarity score (0 – 1)
Separates overlap from net-new rows in the resulting download file

Fuzzy match · file_a.csv ↔ file_b.csv

File A

CompanyContact

Acme Inc.Jen Walsh

Northstar LogisticsMarcus Lee

Helix BioPriya Shah

Kobo StudiosAiko Tanaka

File B

CompanyContact

ACME, IncorporatedJennifer Walsh

North Star Logistics LLCMarc Lee

Helix BiotechPriya S.

Kobo Studio Co.Aiko Tanaka

Fuzzy matches

File AFile BScore

Acme Inc. · Jen WalshACME, Incorporated · Jennifer Walsh0.94

Northstar Logistics · Marcus LeeNorth Star Logistics LLC · Marc Lee0.89

Helix Bio · Priya ShahHelix Biotech · Priya S.0.92

Kobo Studios · Aiko TanakaKobo Studio Co. · Aiko Tanaka0.97

Why Clean

What Excel, LLMs and online tools miss when fuzzy matching two files

Capability	Excel / Power Query	LLMs (ChatGPT, Claude)	Other online tools	Clean
AI-recommended matching columns
Match on multiple columns at once
Token sorting / normalised text tokens
Punctuation & company suffix removal
Case-insensitive + fuzzy text matching
Handles 50k+ rows reliably
Accuracy based on our public benchmark
Browser-based, no install

For the full methodology and results, read our public fuzzy-match benchmark →

Possible Limited Not Possible

Simple Pricing

Free for small files. Pay only for large Excel & CSV jobs.

Process up to 500 rows for free. Larger files are priced per run.

Up to 500 rows

Fuzzy deduplication
Multi-column matching
Instant download

Large File

$1.99+

501 – 100,000 rows

Up to 3,000 rows — $1.99
Up to 10,000 rows — $4.99
Up to 25,000 rows — $9.99
Up to 50,000 rows — $19.99
Up to 100,000 rows — $29.99

Monthly Unlimited

$99.99/mo

Unlimited uploads

Up to 10 MB per file
Unlimited file upload / deduplication
Priority customer support
Cancel anytime

Learn more

Guides for matching two lists

Step-by-step articles on reconciling CRM imports, trade-show lists, and vendor exports.

Fuzzy Matching Two CSV Files Online in 2026: We Tested 7 Tools on 2,050 Rows

We tested 7 online tools on two CSVs with 950 known fuzzy matches across seven identity fields. Clean recovered 949 of 950 — here is why it outperformed.

How to Join Two CSV Files Online in 2026 — Not Just Stack Them Together

Most online CSV merge tools only stack files together. Here's how to actually match rows and combine columns from two CSV or Excel files — on one column or several at once.

How to Match Two Spreadsheets by Name When You Don't Have a Shared Email

When two spreadsheets don't share a common email address, matching by name is the only option — but VLOOKUP on names fails. Here's what actually works.

How to Find Overlap Between Two Email Lists Before Sending a Campaign

Sending a cold outreach campaign to existing customers is an easy mistake to make — and hard to undo. Here's how to find the overlap between two email lists before hitting send.

The Best Free Match2Lists Alternative for Fuzzy Matching Two Lists

Match2Lists starts at $95/month with no free tier. Here are the best alternatives for fuzzy matching two CSV files — including a free option that handles name variants and multi-column matching.

How to Compare Two Contact Lists Without Excel

Excel's VLOOKUP misses contacts with different name spellings or missing emails. Here's how to compare two contact lists and actually find all the overlap — no formulas required.

How to Check If Your Apollo Export Overlaps with Your Existing CRM Data

Before importing an Apollo, ZoomInfo, or Lusha export, find out how many of those contacts already exist in your CRM — and which ones are genuinely new.

How to Find Net-New Contacts from a Trade Show Lead List

Not everyone who scanned their badge at your booth is a new lead. Here's how to find out which contacts from a trade show are genuinely new before you import them to your CRM.

VLOOKUP Alternative: Fuzzy Match Two Lists When Names Don't Match

VLOOKUP returns #N/A when names are spelled differently. Here's what to use instead when you need to match two lists where the data isn't perfectly consistent.

How to Check If Contacts Are Already in Your CRM Before Importing

Every CRM deduplicates on exact email match — which means name variants slip through as new records. Here's how to actually check which contacts already exist before you import.

How to Fuzzy Match Two Lists: Trade Show Export vs CRM (No Code)

VLOOKUP misses contacts that exist under a different name or email. Here's how to fuzzy match two lists — trade show exports, enriched leads, CRM exports — to find who's already there before you create duplicates.

See all guides

NEED MORE?

Interested in deduping larger files?

Our API handles millions of rows with sub-second matching, bulk uploads, and programmatic access. Or reach out and we'll walk you through a custom solution — free of charge.

FAQ

Frequently asked questions

What is fuzzy matching, and when do I need it?

Fuzzy matching finds rows that refer to the same thing — same person, company, product — even when the values are not character-for-character identical. "Acme Inc." vs "ACME, Incorporated", "Jen Walsh" vs "Jennifer Walsh", an extra space, a trailing comma, a different casing — VLOOKUP and exact joins treat all of these as different rows. You need fuzzy matching whenever your two files come from different systems, different people, or different points in time. More on the underlying problem in Fuzzy Matching in Excel (2026).

Can I fuzzy match on more than one column?

Yes. Pick one column or several — for example match on first name + last name + company, or product name + brand. Clean scores the combination, not each column in isolation, so two rows only count as a match when the full identity lines up.

How does Clean decide what's a match and what isn't?

Every candidate pair gets a similarity score between 0 and 1. You set a threshold — Clean recommends one based on your data — and only pairs above the threshold are returned as matches. You can preview the results and adjust the threshold before paying, so borderline cases never get silently merged or silently dropped.

How is this different from VLOOKUP, XLOOKUP, or Power Query Fuzzy Merge?

VLOOKUP and XLOOKUP only return matches when the lookup value is identical character-for-character — they fail on the messy real-world variants fuzzy matching is meant to catch. Power Query's Fuzzy Merge is closer, but it is Windows-only, slow past a few thousand rows, and gives you very little control over scoring or multi-column matching. Clean runs in any browser, supports composite keys, returns a score for every match, and handles up to 100,000 rows per file. Background reading in Fuzzy Matching Two CSV Files Online (2026).

Is my data safe to upload?

Both files are processed in memory and deleted immediately after your session. They are never written to permanent storage, never shared, and never used for any purpose other than generating your results. You can verify this in our privacy policy.

What file formats are supported?

CSV, XLSX, and XLS. Maximum 10 MB per file. If your files are larger, contact us — we can run them via the API.

Fuzzy match two CSV filesin seconds