100% Browser-Based · File Contents Never Uploaded

Extract Emails, Phone Numbers & SSNs From CSV — Without Uploading Them

Pull emails, phone numbers, credit cards, SSNs, URLs, dates, IP addresses, and ZIP codes from any CSV or text file — with validation, normalization, and zero uploads. The only pattern extractor built for data that cannot leave your machine.

8 pattern types
100% private processing
Luhn + SSA validation
No installation

Used by data analysts, compliance teams, and auditors handling regulated datasets.

Three reasons the current options don't work

Online tools require an upload

Every web-based extractor wants your file. Customer lists. Medical records. Financial exports. Uploading PII to a third-party server is a compliance violation — not a workflow.

Python regex requires coding

Writing re.findall() patterns that correctly handle edge cases — Luhn validation, international phone formats, date ambiguity — takes 20–30 minutes per pattern type, and breaks when data is dirty.

grep misses edge cases silently

grep finds strings that look like patterns. It does not validate them. 078-05-1120 passes a 9-digit SSN regex. 4111111111111112 fails Luhn but matches the CC pattern. You get results with unknown accuracy.

Regex-only extraction produces 30–40% false positives in unstructured text fields (internal testing, Feb 2026). Varies by dataset and field type.

What Makes This Different From a Regex Script

This is not just regex wrapped in a UI.

8 Pattern Types With Real Validation

Email (RFC 5322), Phone (NANP + international), URL, Date (12+ formats), Credit Card (Luhn), SSN (SSA rules), IP Address, ZIP Code — not just regexes, but validators.

Alternatives fall short here
grep/awk: Returns anything matching the pattern. No Luhn check for CCs, no SSA rules for SSNs. False positive rate on unstructured text can exceed 40%.
Validated matches you can act on, not just pattern matches you have to re-verify

Three Validation Modes

Permissive (widest net), Balanced (format rules applied), Strict (deep validation — Luhn, SSA, area codes). Match mode to your use case.

Alternatives fall short here
Python re: Single regex per pattern. Adding Luhn or area code checks requires writing and maintaining custom validation functions for each type.
One setting controls precision vs. recall across all 8 pattern types simultaneously

Post-Extraction Normalization

Phone to E.164 (+15551234567), email to lowercase, date to ISO 8601, URL protocol enforcement — applied after extraction, adds minimal overhead.

Alternatives fall short here
Online extractors: Export raw matches with inconsistent formatting. Loading into a CRM or database requires a second normalization pass.
Import-ready output — consistent formats without a second cleanup step

Column-Level Targeting

For CSV and Excel files, select exactly which columns to scan. Eliminates noise from scanning columns that cannot contain the patterns you need.

Alternatives fall short here
grep: Scans entire file. Scanning a 50-column CRM export for emails finds false matches in URL columns, description fields, and header rows.
Faster processing, higher precision, less noise in results

Context View Per Match

100 characters of surrounding text shown per match with the pattern highlighted. Trace exactly where each value came from.

Alternatives fall short here
Python re.findall(): Returns a flat list of matches with no surrounding context. Identifying where a match appears requires re-running with match.start()/end().
Audit-ready evidence for compliance reviews — every match traceable to its source

Sensitive Data Masking in UI

Credit card numbers and SSNs are masked in the results table (last 4 visible only). Context view obscures mid-digits. Export controls let you decide whether to include full values.

Alternatives fall short here
Every other tool displays extracted PII in plain text by default. Screenshots of results become compliance liabilities.
Review results without creating additional exposure — full values only in controlled exports

5M+ Rows Supported

5M rows processed in 45 seconds (Chrome 131, Windows 11, i7-12700K, 32GB RAM, Feb 2026). Results vary by hardware, browser, and pattern complexity.

Alternatives fall short here
Online tools: Typical upload limits of 10–50MB. A 5M-row export is 400–600MB — well over most limits, requiring splitting the file manually first.
Process full exports without pre-splitting, regardless of file size

Privacy by Architecture, Not Policy

File contents never leave your browser. No server receives your data at any point. HIPAA, GDPR, PCI-DSS, and SOX compliance is structural — there is no data transmission to govern.

Alternatives fall short here
Every cloud-based tool: Files transmitted over HTTPS, stored on third-party servers during processing. Even with deletion promises, transmission occurred.
Zero transmission risk — the only architecture that eliminates upload-related compliance exposure

SplitForge vs. The Alternatives

When you're extracting PII from production data, the tool choice is a compliance decision

Capabilitygrep / awkPython re / pandasOnline ExtractorsSplitForge
No upload required (PII-safe)
Local
Local
Uploads file
Browser-only
Requires no coding
CLI required
Python required
Point and click
No code needed
Luhn CC validation
No
Write it yourself
Varies by tool
Built-in
SSA-rule SSN validation
No
Write it yourself
No
Built-in
Post-extraction normalization
No
Write it yourself
No
E.164, ISO, etc.
Context view per match
grep -C flag
Manual with span()
No
Built-in, 100 chars
Sensitive data masking in UI
Plain text output
Plain text output
Plain text output
CC + SSN masked
Column-level targeting
awk field selector
df column access
Scans entire file
Column grid UI
Multi-sheet Excel support
No
openpyxl required
Usually no
Yes, sheet selector
File size limit
Unlimited
RAM-bound
10–50MB typical
1GB+ tested

Which Tool Is Right for You?

No single tool is right for every situation. Here's an honest breakdown.

Use grep / awk if:

  • You need automation in a shell script or CI pipeline
  • You're comfortable with regex and command-line tools
  • The data is not PII (log files, URLs, non-sensitive identifiers)
  • Speed on very large files (>10GB) matters more than validation accuracy
  • You don't need a UI or formatted export — raw output is fine

Use Python re / pandas if:

  • You need to run this on a schedule or inside a data pipeline
  • You need custom regex patterns beyond the 8 built-in types
  • You're processing 50M+ row files where browser limits apply
  • You're comfortable writing and maintaining Python code
  • Extraction is part of a larger ETL or transformation workflow

Use online extractors only if:

  • The data contains no PII, PHI, or sensitive business information
  • Your organization has no data residency or compliance requirements
  • The file is under the tool's size limit (typically 10–50MB)
  • You've reviewed the tool's data retention and deletion policies
Never upload customer data, healthcare records, financial exports, or employee data to online tools.

Use SplitForge if:

  • Your data contains PII, PHI, or regulated financial information
  • You don't write Python — or don't want to for a one-off extraction task
  • You need Luhn, SSA, or area code validation without writing it yourself
  • You want normalization (E.164, ISO dates) in the same step as extraction
  • You need context view for audit trails or compliance review
  • File size exceeds online tool limits but stays under ~1GB
  • You process this type of file regularly and want a consistent, repeatable workflow

Real-World Use Cases

CRM Data Audit

Source column
notes (free-text field)
"Called customer - 555-903-2847 - follow up with [email protected] by Fri"
Extracted
Phone | Email
(555) 903-2847 | [email protected]
Column targeting scans only the notes column, not all 40 CRM fields. Normalization formats phone for database import.

Healthcare Records De-identification

Source column
clinical_notes
"Patient DOB 03/12/1981, SSN 287-54-9302, contact 617-555-0192"
Extracted
SSN | Phone | Date
XXX-XX-9302 | (617) 555-0192 | 1981-03-12
SSNs masked in UI. Strict mode validates SSA rules. Dates normalized to ISO 8601. File never leaves the browser.

E-commerce Fraud Review

Source column
order_comments
"Ship to card 4532-0151-4872-9941 — billing 90210 — alt contact 323-555-8847"
Extracted
Credit Card | ZIP | Phone
****-****-****-9941 | 90210 | (323) 555-8847
Luhn validation confirms the CC number is structurally valid. Masked in results. PCI-DSS safe by architecture.

Edge Cases That Break Simple Regex

When to Use Pattern Extraction — And When Not To

Built for these workflows

  • HIPAA de-identification audits: finding PHI in free-text clinical notes
  • CRM data quality: extracting contact info from unstructured fields before import
  • PCI-DSS compliance: locating card numbers in transaction exports or comment fields
  • GDPR data subject requests: identifying all personal data in a customer export
  • HR data cleanup: extracting phone and email from legacy free-text records
  • Marketing list validation: extracting and normalizing emails before sending
  • Support ticket analysis: pulling contact info from ticket body text at scale
  • Financial audit prep: identifying SSNs or account numbers in unstructured fields
  • E-commerce fraud review: finding card numbers or IDs in order comments

Honest limitations

  • ~1GB browser ceiling — files larger than this require Python or server-side tools
  • No custom regex — 8 built-in types only; user-defined patterns not yet supported
  • No automation or API — cannot run on a schedule or inside a data pipeline
  • One file per session — no batch scanning across multiple files simultaneously
  • 1M pattern result cap — very dense files may hit this ceiling before scan completes
For automation: Python re + pandas, or AWS Comprehend for entity extraction at pipeline scale. For very large files: Split first with CSV Splitter, then scan each chunk.

Security Architecture

Privacy by architecture, not policy — what that actually means

No telemetry on file contents
SplitForge collects anonymous usage events (tool opened, export triggered) but zero information about your file contents, extracted values, or column names. File data never reaches any analytics endpoint.
No file caching or storage
Files are read into browser memory via the FileReader API and passed directly to the Web Worker. No file data is written to localStorage, IndexedDB, or any persistent browser storage at any point.
Worker memory cleared on unload
The Web Worker processing your file is terminated when you navigate away or close the tab. Browser memory holding file contents and extracted results is released. No residual data persists after the session.
Zero server transmission
The tool's JavaScript runs entirely in your browser. There is no server endpoint that receives file data — not for processing, not for validation, not for logging. Transmission risk is architectural zero, not contractual.

How Much Time Does Scripting Each Extraction Cost You?

Calculate your annual time savings vs. writing Python regex scripts per task

Manual baseline: ~20 minutes per extraction task via Python scripting (internal workflow testing, February 2026). Covers: writing the regex per pattern type, handling encoding edge cases, testing against sample rows, debugging false positives, running on the full file, and validating output counts. SplitForge processes any combination of the 8 built-in pattern types in a single pass with results visible in ~45 seconds (balanced mode, dataset-dependent). Non-coders with PII data have no safe manual alternative — online tools require an upload.

Typical: 2–4 types (email + phone + date)

Monthly = 12, Weekly = 52

Analyst avg: $45–75/hr

Annual Time Saved
51.4
hours per year
Annual Labor Savings
$2,568
per year (vs. scripting each extraction)
VERIFIED BENCHMARK — Last tested: February 2026

551,646 Patterns Extracted in 45 Seconds

5 million rows, 6 pattern types active, balanced validation mode — entirely in your browser with zero server transmission.

File Size
~640 MB
Total Rows
5M
Processing Time
~45 sec
Throughput
~111K/sec
Test config: Chrome 131 (stable), Windows 11, Intel i7-12700K, 32GB RAM, February 2026
Operation: Balanced validation, 6 pattern types active, deduplication off
Method: 10 runs, highest/lowest discarded, remaining 8 averaged
Variance: Results vary by hardware, browser, pattern count, and validation mode (±15–20%)

Frequently Asked Questions

Extract Sensitive Data. Keep It That Way.

8 pattern types. Luhn + SSA validation. Normalization to E.164 and ISO formats. Results stay in your browser. File contents never transmitted.

5M+ rows supported
100% private — file contents never uploaded
Luhn algorithm + SSA rule validation built-in
No installation, no account required

Also try: Data Masking · Data Cleaner · Data Validator · Remove Duplicates