REST vs SOAP vs GraphQL comparison in Rest API - Visual Side-by-Side Comparison

Concept Flow - REST vs SOAP vs GraphQL comparison

Client sends request

↓

REST

↓

Uses HTTP

↓

Stateless

↓

Resource

↓

URLs

↓

JSON/XML

↓

Multiple

↓

Endpoints

↓

Cache

↓

Client receives response

Client sends a request, chooses REST, SOAP, or GraphQL, each with different protocols and data formats, then receives a response.

Execution Sample

Rest API

GET /users/123 HTTP/1.1
Host: api.example.com

--- REST example

POST /soap HTTP/1.1
Host: api.example.com
Content-Type: text/xml

<soapenv:Envelope>...</soapenv:Envelope>

--- SOAP example

POST /graphql HTTP/1.1
Host: api.example.com
Content-Type: application/json

{"query": "{ user(id: \"123\") { name } }"}

--- GraphQL example

Shows example requests for REST, SOAP, and GraphQL APIs fetching user data.

Execution Table

Step	API Type	Request Sent	Data Format	Response Received	Notes
1	REST	GET /users/123	JSON or XML	User data in JSON	Simple URL, stateless
2	SOAP	POST /soap with XML envelope	XML	User data in XML	Strict protocol, built-in security
3	GraphQL	POST /graphql with query JSON	JSON	User data shaped by query	Single endpoint, flexible data
4	REST	GET /users/123	JSON or XML	404 Not Found if user missing	Standard HTTP status codes
5	SOAP	POST /soap with XML envelope	XML	SOAP Fault message	Standardized error handling
6	GraphQL	POST /graphql with query JSON	JSON	Errors in response body	Errors returned in data structure
7	REST	GET /users	JSON or XML	List of users	Multiple endpoints for resources
8	SOAP	POST /soap with XML envelope	XML	Response with multiple data	Complex operations supported
9	GraphQL	POST /graphql with query JSON	JSON	Custom shaped list of users	Client controls data shape
10	Exit	-	-	-	All requests processed

💡 All API types processed their requests and returned responses or errors.

Variable Tracker

Variable	Start	After REST	After SOAP	After GraphQL	Final
Request Type	None	GET /users/123	POST /soap XML	POST /graphql JSON	Completed
Data Format	None	JSON/XML	XML	JSON	Completed
Response	None	User JSON	User XML	User JSON shaped	Completed
Error Handling	None	HTTP status	SOAP Fault	Errors in JSON	Completed

Key Moments - 3 Insights

Why does SOAP always use XML while REST can use JSON or XML?

SOAP is a protocol that requires XML envelopes for messages (see execution_table rows 2 and 5). REST is more flexible and can use JSON or XML depending on the API design (rows 1 and 4).

How does GraphQL let clients control the data shape?

GraphQL uses queries sent in JSON that specify exactly what fields are needed (execution_table row 3 and 9). This means clients get only the data they ask for, unlike REST or SOAP.

Why does REST use multiple endpoints but GraphQL uses a single endpoint?

REST maps resources to URLs (execution_table rows 1 and 7), so each resource has its own endpoint. GraphQL uses one endpoint and clients specify queries to get different data shapes (rows 3 and 9).

Visual Quiz - 3 Questions

Look at the execution table, what data format does SOAP use in its requests?

A Plain text

B JSON

C XML

D YAML

💡 Hint

Check the 'Data Format' column for SOAP rows (2 and 5) in the execution table.

At which step does GraphQL return errors inside the response body?

A Step 6

B Step 9

C Step 3

D Step 2

💡 Hint

Look for 'Errors in response body' in the 'Notes' column for GraphQL in the execution table.

If REST used a single endpoint like GraphQL, what would change in the execution table?

A SOAP would stop using XML

B Multiple endpoints rows would merge into one

C GraphQL would use multiple endpoints

D Error handling would change

💡 Hint

Refer to the 'Notes' column about endpoints in REST and GraphQL rows.

Concept Snapshot

REST, SOAP, and GraphQL are ways to build APIs.
REST uses multiple URLs and supports JSON or XML.
SOAP uses XML with strict rules and built-in security.
GraphQL uses one endpoint and lets clients ask for exactly what they want.
REST is simple and cacheable; SOAP is strict and secure; GraphQL is flexible but complex.

Full Transcript

This visual compares REST, SOAP, and GraphQL APIs. The client sends a request choosing one API type. REST uses HTTP methods and multiple URLs, returning JSON or XML. SOAP sends XML envelopes with strict rules and built-in security. GraphQL uses a single HTTP endpoint with JSON queries that specify exactly what data the client wants. The execution table shows example requests and responses for each API type, including how errors are handled. Variables track request types, data formats, responses, and error handling across the three APIs. Key moments clarify why SOAP uses XML, how GraphQL controls data shape, and why REST uses multiple endpoints. The quiz tests understanding of data formats, error handling, and endpoint differences. The snapshot summarizes the main differences simply and clearly.

Practice

1. Which API style allows clients to request exactly the data they need in a single query?

easy

A. FTP

B. REST

C. SOAP

D. GraphQL

Solution

1. Step 1: Understand GraphQL's data fetching

   GraphQL lets clients specify exactly which fields they want in a query, reducing over-fetching.

2. Step 2: Compare with REST and SOAP

   REST uses fixed endpoints and HTTP methods, SOAP uses strict XML messages, neither allows flexible data selection like GraphQL.

3. Final Answer:

   GraphQL -> Option D

4. Quick Check:

   Exact data request = GraphQL [OK]

Hint: GraphQL = precise data queries in one request [OK]

Common Mistakes:

• Confusing REST with GraphQL's flexible queries
• Thinking SOAP supports flexible data selection
• Choosing unrelated protocols like FTP

2. Which of the following is the correct HTTP method typically used by REST APIs to update a resource?

easy

A. PUT

B. POST

C. GET

D. CONNECT

Solution

1. Step 1: Recall REST HTTP methods

   REST commonly uses PUT to update or replace a resource at a URL.

2. Step 2: Differentiate from other methods

   GET retrieves data, POST creates new resources, CONNECT is for network tunnels, so only PUT updates.

3. Final Answer:

   PUT -> Option A

4. Quick Check:

   Update resource = PUT [OK]

Hint: PUT method updates resources in REST [OK]

Common Mistakes:

• Using GET to update data
• Confusing POST with update instead of create
• Selecting non-REST HTTP methods like CONNECT

3. Given the following GraphQL query, what data will the client receive?

{ user(id: "123") { name email } }

medium

A. {"user": {"name": "Alice"}}

B. {"user": {"name": "Alice", "email": "[e-mail]"}}

C. {"user": {"id": "123", "name": "Alice"}}

D. {"user": {"email": "[e-mail]"}}

Solution

1. Step 1: Analyze the GraphQL query fields

   The query requests the user's name and email fields for user with id "123".

2. Step 2: Determine expected response

   The response includes both requested fields inside the user object, matching {"user": {"name": "Alice", "email": "[e-mail]"}}.

3. Final Answer:

   {"user": {"name": "Alice", "email": "[e-mail]"}} -> Option B

4. Quick Check:

   Requested fields = name and email [OK]

Hint: GraphQL returns only requested fields in response [OK]

Common Mistakes:

• Expecting all user fields returned
• Missing one of the requested fields
• Confusing id field presence

4. You have a SOAP API call that fails due to incorrect message format. What is the most likely cause?

medium

A. Using GraphQL query syntax in the request

B. Missing HTTP GET method in the request

C. Using JSON instead of XML in the request body

D. Not specifying the resource URL correctly

Solution

1. Step 1: Understand SOAP message format requirements

   SOAP requires XML formatted messages strictly following its schema.

2. Step 2: Identify common format errors

   Sending JSON instead of XML breaks the SOAP message format, causing failure.

3. Final Answer:

   Using JSON instead of XML in the request body -> Option C

4. Quick Check:

   SOAP needs XML, not JSON [OK]

Hint: SOAP messages must be XML formatted [OK]

Common Mistakes:

• Using JSON payloads with SOAP
• Confusing HTTP methods for SOAP
• Mixing GraphQL syntax with SOAP

5. You need to design an API for a mobile app that requires minimal data usage and flexible queries. Which API style is best and why?

hard

A. GraphQL, because it lets clients request exactly the data they need

B. REST, because it uses simple URLs and HTTP methods

C. SOAP, because it uses strict XML for secure communication

D. FTP, because it transfers files efficiently

Solution

1. Step 1: Identify requirements for minimal data and flexible queries

   The app needs to reduce data usage and allow clients to specify data fields.

2. Step 2: Match API styles to requirements

   GraphQL allows clients to request only needed data in one query, minimizing data transfer and providing flexibility.

3. Final Answer:

   GraphQL, because it lets clients request exactly the data they need -> Option A

4. Quick Check:

   Minimal data + flexible queries = GraphQL [OK]

Hint: Choose GraphQL for flexible, minimal data queries [OK]

Common Mistakes:

• Choosing REST without flexible data selection
• Selecting SOAP despite heavy XML overhead
• Confusing FTP with API styles