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No Upload Required β€” 100% Browser-Based

Validate Any CSV or Excel File Before It Breaks Your CRM Import

Stop discovering data errors after a failed Salesforce import. Data Validator catches malformed emails, missing required fields, invalid formats, and duplicate records before you upload β€” saving hours of back-and-forth. Read why CRMs reject 30% of imports or how to validate CSV files automatically.

12 validation rule types. 20+ data types including NPI, ICD-10, and CPT codes. 15+ CRM/database presets. Blocking vs warning error levels. Export failed rows separately.

What is Data Validator?

Data Validator is a browser-based tool that checks your CSV or Excel file against validation rules before you import it anywhere. You define what "valid" means for each column β€” required fields, data formats, allowed values, uniqueness constraints β€” and Data Validator tells you exactly which rows fail and why. All processing runs locally in your browser. No files are uploaded.

Validation Rule Types
required, dataType, length, range, regex, enum, uniqueness
CRM/Database Presets
Salesforce, HubSpot, PostgreSQL, MySQL, and more
Max Rows Tested
~270K rows/sec (full schema), ~500K rows/sec (simple)
Healthcare Data Types
NPI, ICD-10, CPT, SSN, taxonomy codes

The CRM Import Cycle of Pain

Without Data Validator

Every week, for millions of data teams:

  • β€’ Export CRM contacts from old system or spreadsheet
  • β€’ Open in Excel to "do a quick check"
  • β€’ "Looks fine." Upload to Salesforce/HubSpot.
  • β€’ Wait 15 minutes for the import job
  • β€’ Salesforce returns: "Import failed β€” 847 errors"
  • β€’ Error file shows: Row 2847: Email field exceeds maximum length (82 > 80 chars)
  • β€’ Manually fix errors. Re-upload. Repeat 2–3 more times.
  • β€’ Total time lost: 2.5+ hours per failed import cycle.
Excel's Data Validation limits: 256 rules max per worksheet, no regex support, no uniqueness checking, no export of failed rows. Read the full breakdown β€” why Excel fails for CRM validation.
With Data Validator

Same workflow, 11 minutes instead of 2.5 hours:

  • β€’ Export CRM contacts from old system or spreadsheet
  • β€’ Drop CSV into Data Validator. Select "Salesforce Contacts" preset.
  • β€’ 8 seconds: validation complete. 847 errors found β€” all listed with row, column, rule, and value.
  • β€’ Export failed rows CSV. Bulk fix in Excel or Data Cleaner.
  • β€’ Re-validate. 0 blocking errors.
  • β€’ Upload to Salesforce. Import succeeds on first attempt.
  • β€’ Total file never left your browser β€” PHI stayed local.
  • β€’ Total time: ~11 minutes.
Result: 2.5 hours β†’ 11 minutes. No repeated upload failures. No 15-minute wait cycles per attempt.

The Real Cost of Failed Imports

Manual validation (per import cycle):
β€’ 3 upload attempts Γ— 15 min wait = 45 min
β€’ Excel cleanup per attempt = 30–45 min
β€’ Re-formatting + re-uploading = 20 min
β€’ Total per cycle: ~2.5 hours
β€’ At $60/hr data analyst rate
β€’ Cost per cycle: ~$150
With Data Validator (per import cycle):
β€’ Validate CSV: ~8 seconds
β€’ Export failed rows: 2 seconds
β€’ Bulk fix in Excel/Data Cleaner: ~10 min
β€’ Re-validate: 8 seconds
β€’ Total per cycle: ~11 minutes
β€’ Tool cost: $0
β€’ Cost per cycle: ~$11
17% annual savings for teams doing 4+ imports/month. See full ROI calculator β†’

Quick Comparison

FeatureExcel Data ValidationData ValidatorPython / pandas
Row limit1,048,576 rows max10M+ rows testedRAM-limited
Custom regex rulesβœ— (no regex support)βœ“ Full regexβœ“ via re module
Uniqueness checkingβœ—βœ“ Hash-based, 10M rowsβœ— (manual COUNTIF)
No data uploadβœ“ Localβœ“ Browser-onlyβœ“ Local
Recommended whenSimple rules, small files, existing Excel workflowPre-CRM import validation, HIPAA-sensitive files, 12+ rule types, uniqueness requiredScripted pipelines, developers, reproducible workflows

TL;DR β€” What Data Validator does:

  • Rule types: required, dataType, length, range, regex, enum, uniqueness (12 total)
  • Data types: email, phone, URL, date (8 formats), NPI, ICD-10, CPT, SSN, integer, float, boolean, currency, and more (20+)
  • Presets: Salesforce Contacts/Leads, HubSpot CRM, PostgreSQL, MySQL, and 10+ more
  • Error levels: blocking (stops import) vs warning (flagged for review)
  • Export: failed rows CSV, passed rows CSV, validation report JSON
  • Privacy: 100% browser-based β€” file contents never uploaded to any server

Stop the Import Failure Loop

Validate your CSV before the first upload attempt. Catch all blocking errors in seconds β€” not after a 15-minute upload wait and a cryptic error report.

No signup required
File never uploaded
Results in seconds
Not sure if this is the right tool? See how it works

How to Validate a CSV File Before a Salesforce or HubSpot Import

The most common cause of failed CRM imports is data that violates field-level rules the CRM only checks at upload time β€” malformed emails, fields that exceed max length, missing required values, duplicate records. Data Validator checks all of these rules locally in your browser before you attempt an upload. Upload once, import cleanly. See also: how to remove duplicate emails before CRM import for deduplication strategies.

What Data Validator Checks β€” And What Excel Can't

Where Excel Data Validation Fails You

256-rule limit: Excel allows a maximum of 256 Data Validation rules per worksheet. A real Salesforce schema has hundreds of field-level constraints.
No regex: Excel uses ISNUMBER/FIND patterns β€” not true regular expressions. You cannot validate email format, phone patterns, or custom codes accurately.
No uniqueness checking: Excel has no built-in rule to check uniqueness across an entire column at scale. COUNTIF formulas break on files over 100K rows.
No failed row export: Excel highlights invalid cells β€” it doesn't give you a clean export of failed rows ready for bulk fixing.

12 Validation Rule Types

Required (non-empty), dataType (20+ types), length (min/max chars), range (numeric min/max), regex (custom pattern), enum (allowed values list), uniqueness (no duplicates across column), and more. Each rule can be set as blocking (stops import) or warning (flagged for review).

Real-world benefit:
Complete rule coverage for any CRM import schema β€” no workarounds needed.

20+ Data Types

Email (RFC 5322 + common format checks), phone (US formats + international), URL, 8+ date formats (YYYY-MM-DD, MM/DD/YYYY, ISO 8601), integer, float, boolean, currency, NPI (10-digit + Luhn check), ICD-10-CM codes (70K+ valid codes), CPT codes (10K+ AMA codes), SSN, taxonomy codes, and more.

Real-world benefit:
Healthcare data validation without uploading PHI to any server.

Custom Regex Rules

Write your own regular expression for any column β€” product codes, internal IDs, custom date formats, zip code patterns. Regex rules are compiled once and applied across all rows without performance degradation.

Real-world benefit:
Validate formats that no preset can anticipate β€” any pattern, any schema.

Hash-Based Uniqueness Checking

Build a complete hash set of all values in a column and check each row against it β€” across 10M rows in ~37 seconds. No COUNTIF formula that slows down at 100K rows. Validates the Email field for Salesforce duplicate rejection before it happens.

Real-world benefit:
Catch duplicate emails, account IDs, or any unique field before Salesforce rejects your import.

Export Failed / Passed Rows

One-click export of failed rows (for bulk fixing) and passed rows (for immediate import). Each exported row includes the original data, which rules failed, and the invalid values. Ready to open in Excel, Google Sheets, or Data Cleaner.

Real-world benefit:
Fix errors in bulk, not one at a time β€” import your file cleanly on the first attempt.

15+ CRM/Database Presets

Pre-configured rule sets for Salesforce Contacts, Salesforce Leads, HubSpot CRM Contacts, PostgreSQL VARCHAR constraints, MySQL data types, and more. Each preset includes the standard field requirements for that platform β€” select and validate in one step.

Real-world benefit:
No rule configuration needed for common import targets β€” select preset, validate, fix, import.
Plus: blocking vs warning error levels, confidence scoring, Excel multi-sheet support (.xlsx), validation report export (JSON), short-circuit after 100 blocking errors to prevent UI overload on severely corrupt files, and 100% browser-based processing β€” no accounts, no uploads, no per-use fees.

Data Validator vs Excel vs Manual Validation vs Python

FeatureExcel Data ValidationManual ReviewData Validator
Import Failure PreventionPartial β€” misses regex, uniqueness, lengthPartial β€” human error, slowComplete β€” 12 rule types, all enforced
Row limit1,048,576 rows hard limitImpractical beyond 10K rows10M+ rows tested
Regex rulesNo (ISNUMBER patterns only)Yes β€” any pattern
Uniqueness checkingNo (COUNTIF breaks at scale)Yes β€” hash-based, 10M rows
Export failed rowsYes β€” clean CSV ready for bulk fix
Healthcare data types (NPI/ICD-10)No (manual code lookup)Yes β€” built in
CRM presetsNo15+ (Salesforce, HubSpot, PostgreSQL...)
Data privacyLocal (no upload)Depends on workflow100% browser-based β€” never uploaded
CostMicrosoft 365 required$60–$100+/hr analyst timeFree
Recommended whenSimple rules + small files in existing Excel workflowTiny files + no tooling availableAny file over 10K rows, CRM imports, healthcare data, regex/uniqueness rules required

Real-World Validation Scenarios

Salesforce Contacts Import β€” 87,000 Rows

A sales ops team exports 87,000 contacts from their old CRM. Without validation, they'd discover errors only after Salesforce rejects the import.

Before (without Data Validator):
  • β€’ Upload to Salesforce β€” wait 15 minutes
  • β€’ Import fails: 1,859 errors
  • β€’ Error file: row-by-row, one error per row shown
  • β€’ Fix 200 rows manually β€” re-upload
  • β€’ Fails again: 800 more errors not shown in first attempt
  • β€’ 3 upload cycles later: finally imports
  • β€’ Total time: 2.5+ hours
After (with Data Validator):
  • β€’ Drop CSV β†’ select Salesforce Contacts preset
  • β€’ 8 seconds: 1,859 errors identified, all at once
  • β€’ Error breakdown: 1,247 email length > 80 chars, 412 duplicate emails, 200 missing LastName
  • β€’ Export failed rows CSV
  • β€’ Bulk fix in Data Cleaner (truncate emails, deduplicate, fill required fields)
  • β€’ Re-validate: 0 blocking errors
  • β€’ Upload to Salesforce β€” imports cleanly
  • β€’ Total time: 11 minutes
Outcome: First-attempt import success, 2.5 hours saved. See also: why Salesforce rejects CSV imports.
Healthcare Claims File β€” 45,000 NPI Codes

A healthcare billing team needs to validate NPI, ICD-10, and CPT codes in a claims file before submission. All data must stay local β€” PHI cannot leave the browser.

Result: Data Validator validated all NPI codes (Luhn algorithm), ICD-10 codes (against 70K+ valid FY2026 codes), and CPT codes (AMA code set) without uploading any patient data.
PHI never left the browserRelated reading β†’
Inventory Data Migration β€” 12,000 SKUs

An e-commerce team migrates product data between platforms. Every SKU must have a unique identifier, valid price format, and required category field.

Result: Uniqueness rule caught 247 duplicate SKUs. Range rule flagged 18 products with negative prices. Required rule identified 92 products missing category.
357 errors caught pre-migrationRelated reading β†’

Technical Deep Dive: How Data Validator Handles Edge Cases

Honest documentation of validation behavior on tricky real-world data.

Email Validation β€” What "Valid" Actually Means

Uniqueness Checking at 10M Rows β€” Memory and Performance

NPI, ICD-10, and CPT Validation β€” Healthcare Code Accuracy

Excel / XLSX Validation β€” What Changes vs CSV

Blocking vs Warning β€” When to Use Each

Data Validator Is Perfect For

  • β€’ Pre-import validation before Salesforce, HubSpot, or any CRM
  • β€’ Healthcare data with NPI, ICD-10, CPT codes that must stay local
  • β€’ Files too large for Excel Data Validation (1M+ rows)
  • β€’ Uniqueness checking across millions of rows
  • β€’ Teams where configuring Python validation is too slow
  • β€’ Validation with custom regex rules
  • β€’ Exporting failed rows for bulk fixing
  • β€’ Multiple validation passes β€” validate, fix, re-validate
  • β€’ Database migration data quality checks
  • β€’ One-off file validation where setting up Python scripts is overkill

Not Ideal For

  • β€’ Automated, scheduled, or CI/CD pipeline validation (no API)
  • β€’ Files over ~2GB / 15M rows (browser memory limits)
  • β€’ Streaming or real-time data (batch file only)
  • β€’ Team-shared schemas with version control
  • β€’ Statistical data quality (distributions, outliers) β€” use Data Profiler
  • β€’ Non-CSV/Excel formats (JSON, Parquet, Avro, databases)
  • β€’ Validation that needs to run headlessly on a server
  • β€’ More than 50M rows (use Python Great Expectations)
  • β€’ Validation schemas shared across teams
  • β€’ Integration with dbt, Airflow, or similar workflow orchestration
Rule of thumb: Validate first to find what's wrong. Then clean with Data Cleaner to fix it in bulk. Then re-validate before import.

Performance: Up to 500K Rows/Sec

Verified Benchmark β€” February 2026

Two Validation Modes

Two modes: Simple validation (format checks only, no uniqueness) runs at ~500K rows/sec. Full schema with uniqueness checking runs at ~270K rows/sec at 10M rows. full benchmark methodology β†’
Test hardware: Chrome (stable), Windows 11, Intel Core i5-12600KF (3.70GHz), 64GB RAM. 10 runs per configuration β€” highest/lowest discarded, remaining 8 averaged.
Simple Validation
~500K/s
rows/sec (format + required)
Full Schema
~270K/s
rows/sec (5 rules + uniqueness)
10M Row Test
37s
full schema, Feb 2026
Rule Types
12
all applied per row
37-second benchmark breakdown:
β€’ Test file: 10M rows, Email + FirstName + LastName + Phone + Company
β€’ Rules: Email required + valid format + unique + max 80 chars + LastName required
β€’ 50M individual validation checks total (5 rules Γ— 10M rows)
β€’ Uniqueness hash table for Email column: ~1.2GB peak at 10M unique emails

Frequently Asked Questions

How does Data Validator prevent Salesforce import failures?

What validation rules does Data Validator support?

Can Data Validator handle healthcare data validation?

How fast can Data Validator process large files?

Is my data safe? What about HIPAA compliance?

What's the difference between a blocking error and a warning?

Does Data Validator work with Excel files?

What happens if my file has thousands of errors?

Can I save my validation schema to reuse later?

How does uniqueness checking work across 10M rows?

Why We Built This

Every data team has a story like this: a CRM migration that was supposed to take a day turned into a week because of import failures nobody could fully diagnose until after each upload attempt. The error files were cryptic. Excel's validation rules were inadequate. Python scripts took longer to write than the cleanup itself.

We built Data Validator because the existing options β€” Excel Data Validation (256 rules, no regex, no uniqueness), manual review (impractical at scale), Python scripts (overkill for one-off files) β€” all fail at the moment you need them most: when you have 87,000 contacts to import and a 3 PM deadline.

The principle is simple: validate locally, see all errors at once, export failed rows ready for bulk fixing, re-validate before upload. No failed import cycles. No data leaving your browser.

β€” SplitForge Engineering, 2026

"But I Already Use..."

"I already use Excel Data Validation"

"I just do a manual review in Excel"

"I use Python to validate my data"

"I'll just fix errors after the import fails"

Related Tools

Ready to Validate Your Data?

Stop the import failure loop. Validate your CSV locally, catch all blocking errors at once, and import cleanly on the first attempt.

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File never uploaded
Results in seconds