HTTPie and cURL: Command-Line API Testing Tools Comparison

Introduction

For developers who live in the terminal, command-line API testing tools are indispensable. The two dominant tools in this space—cURL and HTTPie—serve similar purposes but with vastly different philosophies. cURL is the veteran Swiss Army knife available on virtually every system, while HTTPie is the modern, human-friendly alternative designed for developer happiness.

While graphical tools like Insomnia provide intuitive interfaces for API exploration, command-line tools excel in automation and scripting workflows.

cURL: The Universal Standard

Overview

cURL (Client URL) has been the de facto standard for command-line HTTP requests since 1997. It’s pre-installed on most Unix-like systems (Linux, macOS) and Windows 10+, making it universally accessible.

Basic Syntax

GET Request

curl https://api.example.com/users

POST Request

curl -X POST https://api.example.com/users \
  -H "Content-Type: application/json" \
  -d '{"name":"John","email":"john@example.com"}'

With Headers

curl -H "Authorization: Bearer token123" \
  -H "Accept: application/json" \
  https://api.example.com/profile

Save Response

curl -o response.json https://api.example.com/data

Advanced cURL Features

Follow Redirects

curl -L https://api.example.com/redirect

Include Headers in Output

curl -i https://api.example.com/users

Verbose Mode (Debugging)

curl -v https://api.example.com/users

File Upload

curl -F "file=@document.pdf" https://api.example.com/upload

Authentication

# Basic Auth
curl -u username:password https://api.example.com/secure

# Bearer Token
curl -H "Authorization: Bearer $TOKEN" https://api.example.com/api

HTTPie: The Human-Friendly Alternative

Overview

HTTPie (pronounced “aitch-tee-tee-pie”) is a modern command-line HTTP client with intuitive syntax, JSON support, and beautiful output formatting.

Basic Syntax

GET Request

http GET https://api.example.com/users
# or simply:
http https://api.example.com/users

POST Request

http POST https://api.example.com/users name=John email=john@example.com

With Headers

http https://api.example.com/profile \
  Authorization:"Bearer token123" \
  Accept:application/json

Download File

http --download https://api.example.com/file.pdf

Advanced HTTPie Features

JSON Syntax Sugar

# Simple key-value pairs become JSON
http POST https://api.example.com/users \
  name=John \
  age:=30 \
  active:=true \
  tags:='["developer","qa"]'

Form Data

http --form POST https://api.example.com/upload \
  file@document.pdf \
  description="Important document"

Sessions

# Create session
http --session=user1 POST https://api.example.com/login \
  username=john password=secret

# Reuse session (cookies, headers preserved)
http --session=user1 GET https://api.example.com/profile

Pretty Printing

# Automatic syntax highlighting and formatting
http https://api.example.com/users

# Control output format
http --print=HhBb https://api.example.com/users
# H: request headers
# B: request body
# h: response headers
# b: response body

Side-by-Side Comparison

Syntax Comparison

Task	cURL	HTTPie
GET	`curl https://api.com/users`	`http GET https://api.com/users`
POST JSON	`curl -X POST -H "Content-Type: application/json" -d '{"name":"John"}' https://api.com/users`	`http POST https://api.com/users name=John`
Headers	`curl -H "Auth: token" https://api.com`	`http https://api.com Auth:token`
Query Params	`curl "https://api.com/search?q=test&page=1"`	`http GET https://api.com/search q==test page==1`
File Upload	`curl -F "file=@doc.pdf" https://api.com/upload`	`http --form POST https://api.com/upload file@doc.pdf`

Real Example: Create User

cURL

curl -X POST https://api.example.com/users \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer abc123" \
  -d '{
    "name": "Jane Doe",
    "email": "jane@example.com",
    "age": 28,
    "active": true,
    "roles": ["user", "moderator"]
  }'

HTTPie

http POST https://api.example.com/users \
  Authorization:"Bearer abc123" \
  name="Jane Doe" \
  email=jane@example.com \
  age:=28 \
  active:=true \
  roles:='["user","moderator"]'

Scripting and Automation

Command-line tools are essential components of a comprehensive API testing strategy, particularly for automation and continuous integration workflows.

Bash Scripts with cURL

#!/bin/bash

# Configuration
API_BASE="https://api.example.com"
TOKEN="your-api-token"

# Function to make authenticated requests
api_call() {
  local method=$1
  local endpoint=$2
  local data=$3

  curl -X "$method" "$API_BASE$endpoint" \
    -H "Authorization: Bearer $TOKEN" \
    -H "Content-Type: application/json" \
    -d "$data"
}

# Login and get token
TOKEN=$(curl -X POST "$API_BASE/auth/login" \
  -H "Content-Type: application/json" \
  -d '{"username":"admin","password":"secret"}' | \
  jq -r '.access_token')

# Use token for subsequent requests
api_call GET "/users"
api_call POST "/users" '{"name":"Test User","email":"test@example.com"}'

Bash Scripts with HTTPie

#!/bin/bash

API_BASE="https://api.example.com"

# Login and extract token
TOKEN=$(http POST "$API_BASE/auth/login" \
  username=admin password=secret | \
  jq -r '.access_token')

# Make authenticated requests
http GET "$API_BASE/users" "Authorization:Bearer $TOKEN"
http POST "$API_BASE/users" "Authorization:Bearer $TOKEN" \
  name="Test User" email=test@example.com

CI/CD Integration

GitHub Actions with cURL

name: API Tests
on: [push]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - name: Test API Health
        run: |
          response=$(curl -s -o /dev/null -w "%{http_code}" https://api.example.com/health)
          if [ $response -ne 200 ]; then
            echo "API health check failed"
            exit 1
          fi

      - name: Test User Creation
        run: |
          curl -X POST https://api.example.com/users \
            -H "Authorization: Bearer ${{ secrets.API_TOKEN }}" \
            -H "Content-Type: application/json" \
            -d '{"name":"CI User","email":"ci@example.com"}' \
            --fail-with-body

GitLab CI with HTTPie

api_tests:
  stage: test
  image: alpine:latest
  before_script:
    - apk add --no-cache httpie jq
  script:
    - http GET https://api.example.com/health --check-status
    - |
      http POST https://api.example.com/users \
        Authorization:"Bearer $API_TOKEN" \
        name="CI User" \
        email=ci@example.com \
        --check-status

Best Practices

Error Handling

cURL

# Check HTTP status code
http_code=$(curl -s -o /dev/null -w "%{http_code}" "$URL")
if [ "$http_code" -ne 200 ]; then
  echo "Request failed with status $http_code"
  exit 1
fi

# Fail on HTTP errors
curl --fail-with-body "$URL"

# Retry on failure
curl --retry 3 --retry-delay 5 "$URL"

HTTPie

# Exit with error on HTTP error statuses
http --check-status GET https://api.example.com/users

# Download with progress and resume
http --download --continue https://api.example.com/large-file.zip

Environment Variables

# .env file
API_BASE_URL=https://api.example.com
API_TOKEN=your-secret-token

cURL

source .env
curl -H "Authorization: Bearer $API_TOKEN" "$API_BASE_URL/users"

HTTPie

source .env
http "$API_BASE_URL/users" "Authorization:Bearer $API_TOKEN"

Response Processing

With jq (JSON processor)

# cURL + jq
curl https://api.example.com/users | jq '.[] | select(.active == true) | .email'

# HTTPie + jq (although HTTPie has built-in formatting)
http https://api.example.com/users | jq '.[] | select(.active == true) | .email'

Performance Comparison

Speed: cURL is generally faster (C-based) vs HTTPie (Python-based) Memory: cURL uses less memory Startup Time: cURL is nearly instant, HTTPie has slight Python overhead

For most API testing, the difference is negligible. Use HTTPie for interactive use, cURL for performance-critical automation.

When to Use Each

Use cURL When:

✓ Maximum compatibility required
✓ Scripting for production systems
✓ Minimal dependencies needed
✓ Performance is critical
✓ System doesn’t have HTTPie installed

Use HTTPie When:

✓ Interactive API exploration
✓ Developer experience matters
✓ Working primarily with JSON APIs
✓ Readability of scripts important
✓ Can install additional tools

Conclusion

Both cURL and HTTPie are excellent tools with different strengths:

cURL: Universal, fast, ubiquitous, powerful HTTPie: Modern, readable, user-friendly, JSON-focused

For most developers, the ideal setup is:

HTTPie for daily interactive API testing
cURL for scripts and automation where portability matters

Learn both—they complement each other perfectly in a comprehensive API testing toolkit. When comparing different API testing tools in 2025, command-line options like cURL and HTTPie remain essential alongside modern alternatives like REST Assured for Java-based automation.