curlコマンドチートシート：API テスト用50+の例

REST APIのテスト、Webhookのデバッグ、HTTPリクエストの自動化など、curlはすべての開発者に必要な万能ツールです。この包括的なチートシートには、カテゴリ別に整理された50以上のcurlコマンド例が含まれています。

cURLコード変換ツールでcurlコマンドをコードに変換 →

基本HTTPメソッド

curlでのAPIテストの基本。RESTful APIで使用される5つの主要HTTPメソッド：GET、POST、PUT、DELETE、PATCH。

GET Request

The most basic curl command. By default, curl performs a GET request. Use it to retrieve data from any URL.

# Simple GET request
curl https://api.example.com/users

# GET with query parameters
curl "https://api.example.com/users?page=1&limit=10"

# GET and show response headers too
curl -i https://api.example.com/users

# GET only the response headers
curl -I https://api.example.com/users

# GET with a specific HTTP version
curl --http2 https://api.example.com/users

POST Request

Send data to create a new resource. The -X POST flag is optional when using -d since curl automatically uses POST when data is included.

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

# POST with data from a file
curl -X POST https://api.example.com/users \
  -H "Content-Type: application/json" \
  -d @payload.json

# POST with URL-encoded form data
curl -X POST https://api.example.com/login \
  -d "username=admin&password=secret"

# POST and follow redirects
curl -L -X POST https://api.example.com/users \
  -H "Content-Type: application/json" \
  -d '{"name": "John"}'

PUT Request

Replace an entire resource with new data. PUT is idempotent, meaning multiple identical requests have the same effect as a single one.

# PUT to update a resource
curl -X PUT https://api.example.com/users/123 \
  -H "Content-Type: application/json" \
  -d '{"name": "John Updated", "email": "john.new@example.com"}'

# PUT with data from file
curl -X PUT https://api.example.com/users/123 \
  -H "Content-Type: application/json" \
  -d @updated-user.json

DELETE Request

Remove a resource from the server. DELETE requests typically do not require a body.

# DELETE a resource
curl -X DELETE https://api.example.com/users/123

# DELETE with authentication
curl -X DELETE https://api.example.com/users/123 \
  -H "Authorization: Bearer your-token-here"

# DELETE with confirmation body
curl -X DELETE https://api.example.com/users/123 \
  -H "Content-Type: application/json" \
  -d '{"confirm": true}'

PATCH Request

Partially update a resource. Unlike PUT, PATCH only sends the fields that need to be changed.

# PATCH to partially update
curl -X PATCH https://api.example.com/users/123 \
  -H "Content-Type: application/json" \
  -d '{"email": "newemail@example.com"}'

# PATCH with JSON Merge Patch
curl -X PATCH https://api.example.com/users/123 \
  -H "Content-Type: application/merge-patch+json" \
  -d '{"nickname": null, "email": "new@example.com"}'

ヘッダーと認証ヘッダー

HTTPヘッダーでリクエストに追加情報を渡すことができます。認証ヘッダーはAPIで最もよく使われるヘッダーです。

Bearer Token (OAuth 2.0)

# Bearer token authentication
curl https://api.example.com/protected \
  -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIs..."

# Bearer token with POST
curl -X POST https://api.example.com/data \
  -H "Authorization: Bearer your-access-token" \
  -H "Content-Type: application/json" \
  -d '{"key": "value"}'

Basic Authentication

# Basic auth with -u flag (recommended)
curl -u username:password https://api.example.com/protected

# Basic auth with header (manual base64)
curl https://api.example.com/protected \
  -H "Authorization: Basic dXNlcm5hbWU6cGFzc3dvcmQ="

# Prompt for password (more secure)
curl -u username https://api.example.com/protected

Custom Headers

# Set Content-Type
curl https://api.example.com/data \
  -H "Content-Type: application/json"

# Set Accept header
curl https://api.example.com/data \
  -H "Accept: application/xml"

# Multiple custom headers
curl https://api.example.com/data \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -H "X-Request-ID: abc-123" \
  -H "X-API-Version: 2"

# Remove a default header (send empty)
curl https://api.example.com/data \
  -H "User-Agent:"

データの送信

ほとんどのAPI操作にはリクエストボディでのデータ送信が必要です。curlはJSON、フォームデータ、ファイルアップロード、マルチパートリクエストをサポートします。

JSON Body

# Inline JSON
curl -X POST https://api.example.com/users \
  -H "Content-Type: application/json" \
  -d '{"name": "Alice", "age": 30, "roles": ["admin", "user"]}'

# JSON from file
curl -X POST https://api.example.com/users \
  -H "Content-Type: application/json" \
  -d @data.json

# JSON with nested objects
curl -X POST https://api.example.com/orders \
  -H "Content-Type: application/json" \
  -d '{
    "customer": {"id": 123, "name": "Alice"},
    "items": [
      {"product": "Widget", "qty": 2, "price": 9.99},
      {"product": "Gadget", "qty": 1, "price": 24.99}
    ]
  }'

Form Data

# URL-encoded form data (application/x-www-form-urlencoded)
curl -X POST https://api.example.com/login \
  -d "username=admin&password=secret123"

# Form data with --data-urlencode (auto-encodes special chars)
curl -X POST https://api.example.com/search \
  --data-urlencode "query=hello world&special=a+b"

# Read form value from file
curl -X POST https://api.example.com/submit \
  --data-urlencode "essay@essay.txt"

File Upload

# Upload a single file
curl -X POST https://api.example.com/upload \
  -F "file=@/path/to/document.pdf"

# Upload with custom filename
curl -X POST https://api.example.com/upload \
  -F "file=@localfile.jpg;filename=avatar.jpg"

# Upload with content type
curl -X POST https://api.example.com/upload \
  -F "file=@data.csv;type=text/csv"

Multipart Form Data

# File + text fields (multipart/form-data)
curl -X POST https://api.example.com/profile \
  -F "name=Alice" \
  -F "avatar=@photo.jpg" \
  -F "bio=Software developer"

# Multiple files
curl -X POST https://api.example.com/gallery \
  -F "images=@photo1.jpg" \
  -F "images=@photo2.jpg" \
  -F "images=@photo3.jpg"

# Multipart with JSON field
curl -X POST https://api.example.com/submit \
  -F "metadata={\"title\":\"Report\"};type=application/json" \
  -F "attachment=@report.pdf"

認証方法

APIはさまざまな認証メカニズムを使用します。OAuth、APIキー、Cookie、JWTトークンのcurl例です。

OAuth 2.0 Token Flow

# Step 1: Get access token (client credentials)
curl -X POST https://auth.example.com/oauth/token \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=client_credentials" \
  -d "client_id=your-client-id" \
  -d "client_secret=your-client-secret"

# Step 2: Use the token
curl https://api.example.com/resource \
  -H "Authorization: Bearer ACCESS_TOKEN_HERE"

# Refresh an expired token
curl -X POST https://auth.example.com/oauth/token \
  -d "grant_type=refresh_token" \
  -d "refresh_token=your-refresh-token" \
  -d "client_id=your-client-id"

API Key Authentication

# API key in header
curl https://api.example.com/data \
  -H "X-API-Key: your-api-key-here"

# API key in query parameter
curl "https://api.example.com/data?api_key=your-api-key-here"

# API key in Authorization header
curl https://api.example.com/data \
  -H "Authorization: ApiKey your-api-key-here"

Cookie-Based Authentication

# Send cookies with request
curl https://api.example.com/dashboard \
  -b "session_id=abc123; csrf_token=xyz789"

# Save cookies from response to file
curl -c cookies.txt https://api.example.com/login \
  -d "username=admin&password=secret"

# Use saved cookies in subsequent request
curl -b cookies.txt https://api.example.com/dashboard

# Save and send cookies (cookie jar)
curl -b cookies.txt -c cookies.txt https://api.example.com/profile

JWT Token Authentication

# Login to get JWT
curl -X POST https://api.example.com/auth/login \
  -H "Content-Type: application/json" \
  -d '{"email": "user@example.com", "password": "secret"}'

# Use JWT in Authorization header
curl https://api.example.com/protected \
  -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."

# Refresh JWT token
curl -X POST https://api.example.com/auth/refresh \
  -H "Content-Type: application/json" \
  -d '{"refresh_token": "your-refresh-token"}'

デバッグとトラブルシューティング

APIコールが失敗したり予期しない動作をした場合、これらのcurlフラグでHTTPレベルで何が起きているかを確認できます。

Verbose Output (-v)

# Show full request and response headers
curl -v https://api.example.com/users

# Even more verbose (includes SSL handshake)
curl -vvv https://api.example.com/users

# Verbose output to stderr, response to file
curl -v -o response.json https://api.example.com/users

# Trace full data transfer (hex dump)
curl --trace trace.log https://api.example.com/users

# Trace as ASCII
curl --trace-ascii trace.txt https://api.example.com/users

Timing & Performance

# Show detailed timing information
curl -w "\n---TIMING---\nDNS Lookup:    %{time_namelookup}s\nTCP Connect:   %{time_connect}s\nSSL Handshake: %{time_appconnect}s\nServer Process:%{time_starttransfer}s\nTotal Time:    %{time_total}s\nDownload Size: %{size_download} bytes\nHTTP Code:     %{http_code}\n" \
  -o /dev/null -s https://api.example.com/data

# Simple total time only
curl -w "\nTime: %{time_total}s\n" -o /dev/null -s https://api.example.com

# Show HTTP status code only
curl -o /dev/null -s -w "%{http_code}\n" https://api.example.com

# Timing with format file (reusable)
# Create curl-timing.txt with: time_total: %{time_total}\n
curl -w @curl-timing.txt -o /dev/null -s https://api.example.com

Follow Redirects (-L)

# Follow redirects automatically
curl -L https://example.com/short-url

# Follow redirects with a max limit
curl -L --max-redirs 5 https://example.com/short-url

# Show redirect chain
curl -L -v https://example.com/short-url 2>&1 | grep "< HTTP\|< Location"

# Follow redirects but change POST to GET after redirect
curl -L --post301 --post302 -X POST https://example.com/api \
  -d "data=value"

SSL Issues (-k)

# Skip SSL verification (development only!)
curl -k https://self-signed.example.com/api

# Use a custom CA certificate
curl --cacert /path/to/ca-cert.pem https://api.example.com

# Client certificate authentication
curl --cert client-cert.pem --key client-key.pem https://api.example.com

# Show SSL certificate info
curl -vI https://api.example.com 2>&1 | grep -A6 "Server certificate"

# Force TLS version
curl --tlsv1.2 https://api.example.com
curl --tlsv1.3 https://api.example.com

高度な使い方

プロダクションワークフロー向けのcurlパワーユーザー機能：プロキシ、リトライ、レート制限、レスポンスのファイル保存。

Proxy

# Use HTTP proxy
curl -x http://proxy.example.com:8080 https://api.example.com

# Use SOCKS5 proxy
curl --socks5 socks5://proxy.example.com:1080 https://api.example.com

# Proxy with authentication
curl -x http://user:pass@proxy.example.com:8080 https://api.example.com

# Use HTTPS proxy
curl --proxy-cacert proxy-ca.pem -x https://proxy.example.com:443 https://api.example.com

# Bypass proxy for specific hosts
curl --noproxy "localhost,127.0.0.1,.internal.com" \
  -x http://proxy:8080 https://api.example.com

Retry

# Retry on transient errors (3 times)
curl --retry 3 https://api.example.com/data

# Retry with delay between attempts
curl --retry 5 --retry-delay 2 https://api.example.com/data

# Retry with exponential backoff (max wait)
curl --retry 5 --retry-max-time 60 https://api.example.com/data

# Retry on all errors (not just transient)
curl --retry 3 --retry-all-errors https://api.example.com/data

Rate Limiting & Timeouts

# Limit download speed
curl --limit-rate 100K https://example.com/large-file.zip -o file.zip

# Set connection timeout (seconds)
curl --connect-timeout 5 https://api.example.com

# Set maximum time for entire operation
curl --max-time 30 https://api.example.com/slow-endpoint

# Both timeouts together
curl --connect-timeout 5 --max-time 30 https://api.example.com

Save Response to File

# Save with custom filename
curl -o response.json https://api.example.com/data

# Save with remote filename
curl -O https://example.com/files/report.pdf

# Save headers and body separately
curl -D headers.txt -o body.json https://api.example.com/data

# Append to file
curl https://api.example.com/logs >> all-logs.txt

# Download multiple files
curl -O https://example.com/file1.zip -O https://example.com/file2.zip

# Resume interrupted download
curl -C - -O https://example.com/large-file.iso

Other Advanced Options

# Silent mode (suppress progress bar)
curl -s https://api.example.com/data

# Silent but show errors
curl -sS https://api.example.com/data

# Send request from specific network interface
curl --interface eth0 https://api.example.com

# Set custom DNS resolver
curl --resolve api.example.com:443:127.0.0.1 https://api.example.com

# Parallel requests (curl 7.66+)
curl --parallel --parallel-max 5 \
  -O https://example.com/file1.zip \
  -O https://example.com/file2.zip \
  -O https://example.com/file3.zip

# Use a config file
curl -K curl.config https://api.example.com

curlをコードに変換

動作するcurlコマンドができたら、プログラミング言語に変換する必要があります。手動で変換する代わりに、自動変換ツールを使いましょう。

For example, this curl command:

curl -X POST https://api.example.com/users \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer token123" \
  -d '{"name": "Alice", "email": "alice@example.com"}'

Can be converted to Python:

import requests

response = requests.post(
    "https://api.example.com/users",
    headers={
        "Content-Type": "application/json",
        "Authorization": "Bearer token123"
    },
    json={"name": "Alice", "email": "alice@example.com"}
)
print(response.json())

Or to JavaScript (fetch):

const response = await fetch("https://api.example.com/users", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "Authorization": "Bearer token123"
  },
  body: JSON.stringify({
    name: "Alice",
    email: "alice@example.com"
  })
});
const data = await response.json();

Or to Go:

package main

import (
    "bytes"
    "encoding/json"
    "net/http"
)

func main() {
    body, _ := json.Marshal(map[string]string{
        "name":  "Alice",
        "email": "alice@example.com",
    })

    req, _ := http.NewRequest("POST", "https://api.example.com/users",
        bytes.NewBuffer(body))
    req.Header.Set("Content-Type", "application/json")
    req.Header.Set("Authorization", "Bearer token123")

    client := &http.Client{}
    resp, _ := client.Do(req)
    defer resp.Body.Close()
}

Instead of writing these conversions by hand, use our cURL to Code Converter to instantly generate production-ready code in Python, JavaScript, Go, PHP, Ruby, Java, C#, and more.

クイックリファレンス：curlフラグトップ20

最もよく使われるcurlフラグ一覧。この表をブックマークして素早く参照。

フラグ	説明	例
`-X`	Set HTTP method (GET, POST, PUT, DELETE, PATCH)	`-X POST`
`-H`	Add a custom header	`-H "Content-Type: application/json"`
`-d`	Send data in request body	`-d '{"key":"val"}'`
`-F`	Send multipart form data / file upload	`-F "file=@photo.jpg"`
`-u`	Basic authentication (user:password)	`-u admin:secret`
`-o`	Save output to file (custom name)	`-o result.json`
`-O`	Save output using remote filename	`-O`
`-i`	Include response headers in output	`-i`
`-I`	Fetch headers only (HEAD request)	`-I`
`-v`	Verbose output (debug requests)	`-v`
`-s`	Silent mode (hide progress bar)	`-s`
`-S`	Show errors in silent mode	`-sS`
`-L`	Follow redirects (3xx responses)	`-L`
`-k`	Skip SSL certificate verification	`-k`
`-b`	Send cookies (string or file)	`-b cookies.txt`
`-c`	Save response cookies to file	`-c cookies.txt`
`-w`	Write-out format (timing, status code)	`-w "%{http_code}"`
`--retry`	Retry on transient failures	`--retry 3`
`--connect-timeout`	Max time for connection (seconds)	`--connect-timeout 5`
`--max-time`	Max time for entire operation (seconds)	`--max-time 30`

よくある質問

curlとwgetの違いは？

curlはURLでのデータ転送用に設計され、幅広いプロトコルをサポートします。wgetは主にファイルダウンローダーです。APIテストにはcurlが標準です。

curlでJSONデータをPOSTするには？

-X POST -H "Content-Type: application/json" -d でJSONボディを指定します。-dフラグは自動的にPOSTを設定するので-X POSTは技術的には不要です。

curlのSSL証明書エラーを処理するには？

-kまたは--insecureフラグでSSL証明書検証をスキップします。開発用には便利ですが、本番環境では使わないでください。

curlの出力をファイルに保存するには？

-o（小文字）でカスタムファイル名、-O（大文字）でリモートファイル名で保存します。

curlで複数のヘッダーを送るには？

複数の-Hフラグを追加します。-Hフラグの数に制限はありません。

curlでAPIのレスポンス時間を測定するには？

-wフラグとタイミング変数を使用します。総時間、DNS查索時間、接続時間、最初のバイトまでの時間を表示できます。

このチートシートをブックマークしてください。curlコマンドをコードに変換するには、以下のツールをお試しください。

cURLコード変換ツールを試す →