Salesforce Data Migration: Data Import Wizard vs Data Loader vs Data Loader CLI vs Bulk API

 

Introduction

Data migration and data loading are common activities in Salesforce. Whether you're onboarding new customers, migrating legacy data, performing mass updates, or integrating with external systems, choosing the right tool is crucial.

Salesforce provides multiple options:

1. Data Import Wizard
2. Data Loader
3. Data Loader CLI
4. Bulk API

Each tool serves a different purpose and comes with its own limitations and advantages.

1. Data Import Wizard

What is Data Import Wizard?

Data Import Wizard is a browser-based data import tool available directly within Salesforce Setup.

It is designed for administrators and business users who need a simple way to import data without installing software.

According to Salesforce, Data Import Wizard supports: Accounts, Contacts, Leads, Solutions, Campaign Members, Person Accounts, and Custom Objects. It supports imports of up to 50,000 records at a time.

It does not support many standard objects, such as Opportunities, Cases, Products, and others, which typically require Data Loader or APIs.

Supported Operations

✅ Insert

✅ Update

✅ Upsert

❌ Delete

❌ Hard Delete

❌ Export

Example

Suppose ABC Technologies provides a file containing 2,000 Account records.

Account Name,Industry

ABC Technologies,Telecom

XYZ Corp,Healthcare..................etc

Using Data Import Wizard:

Setup

→ Data Import Wizard

→ Launch Wizard

→ Upload CSV

→ Map Fields

→ Import

Limits

Maximum: 50,000 Records  per import operation.

Pros

✅ Browser-based

✅ No installation required

✅ User-friendly

✅ Supports duplicate checking

✅ Good for admins

Cons

❌ Limited object support

❌ No export functionality

❌ Cannot delete records

❌ Not suitable for millions of records

2. Data Loader

What is Data Loader?

Data Loader is a desktop application provided by Salesforce.

It is designed for handling larger datasets and supports more operations than Data Import Wizard.

Supported Operations

✅ Insert

✅ Update

✅ Upsert

✅ Delete

✅ Hard Delete

✅ Export

✅ Export All

Example

Need to update 100,000 Opportunities.  - CSV file with some data

Using Data Loader:

Update

→ Upload CSV

→ Map Fields

→ Execute

Limits

Recommended: Up to 5 Million Records  per operation. 

Pros

✅ Supports all standard objects

✅ Supports custom objects

✅ Export data

✅ Delete capability

✅ Easy mapping

✅ Bulk API support

Cons

❌ Desktop installation required

❌ Manual operation

❌ Less suitable for unattended jobs

3. Data Loader CLI (Command Line Interface)

What is Data Loader CLI?

Data Loader CLI allows automation of Data Loader operations through scripts.

No manual intervention required.

Typically used by:

• Integration teams
• DevOps teams
• Data migration teams

Example

Every night:

ERP System

↓

CSV Generated

↓

Data Loader CLI

↓

Salesforce

Scheduled via:  Windows Task Scheduler   OR  Cron Job

Sample Process:

AccountLoad.bat

↓

process-conf.xml

↓

Data Loader CLI

↓

Salesforce

Data Loader CLI Directory Structure:

DataLoader

│

├── bin

│ ├── process.bat

│ └── encrypt.bat

│

├── conf

│ ├── process-conf.xml

│ ├── config.properties

│ └── accountInsert.sdl

│

├── data

│ └── AccountInsert.csv

│

├── success

│ └── accountSuccess.csv

│

├── error

│ └── accountError.csv

│

└── logs

└── dataloader.log

Pros

✅ Fully automated

✅ Scheduled jobs

✅ No human intervention

✅ Suitable for recurring loads

✅ Reusable

Cons

❌ Initial setup is complex

❌ XML configuration required

❌ Troubleshooting can be difficult

❌ Less user-friendly

When to Use?

Use Data Loader CLI when:

• Daily imports required
• Scheduled jobs needed
• Zero manual processing desired

4. Bulk API

What is Bulk API?

Bulk API is Salesforce's asynchronous processing framework designed for large data volumes.

Instead of processing each record immediately:

Records

↓

Batch Creation

↓

Queue

↓

Asynchronous Processing

This allows millions of records to be processed efficiently.

Example

Migration of:

10 Million Contacts

Using SOAP API would be extremely slow.

Using Bulk API:

10 Million Contacts

↓

Batch Split

↓

Asynchronous Processing

↓

Salesforce

Why Bulk API Exists?

Normal APIs process:   Record-by-Record

Bulk API processes:  Batch-by-Batch   which dramatically reduces processing time.

Pros

✅ Handles millions of records

✅ Faster performance

✅ Reduced API overhead

✅ Ideal for ETL tools

✅ Supports parallel processing

Cons

❌ More complex

❌ Asynchronous

❌ Monitoring required

❌ Locking issues possible

❌ Error handling more difficult

Comparison Table: