Suzi Load Tester

Suzi is a lightweight, flexible, and extensible HTTP load testing tool written in Go. It’s designed for developers and DevOps engineers who want quick insights into application performance without relying on heavy external tools.

Features

• Multiple Attack Types:

  • Basic Load – send a fixed number of requests at a constant rate.
  • Burst Load – hammer the server with a sudden spike of requests.
  • Ramp-Up Load – gradually increase request rate from low to peak.
  • Random Load - send requests in a random manner.

• Latency Percentiles (p50, p90, p95, p99):

  get detailed insights into response time distribution. Useful when need to get over all idea about user experience.

• Result Visualization:

  • Generates an interactive HTML report with charts (response time per request).
  • Includes a latency summary table showing percentile breakdown.

• Configurable Timeout per request:

  simulate slow responses or protect against server hangs. One of the important feature in day-to-day server testing (basic).

• Email Option:

  Email notifications after testing or CI/CD integration can be sent for better review.

Installation

• Clone the repo first:

   git clone https://github.com/Mujib-Ahasan/Suzi.git
   cd suzi
  

• Build the binary:

  go build -o suzi.exe  -> for windows
  go build -o suzi -> for Linux/macOS
  

• Run the examples below:

   -------Disable the timeout and plot function just by removing the flags---------
   //Basic attack
  ./suzi -url https://example.com -req 50 -rate 5 -atk basic -timeout 5 -plot true
  
   //Burst attack
  ./suzi -url https://example.com -req 50 -atk burst -timeout 5 -plot true
  
   //Ramp-Up attack
  ./suzi -url https://example.com -req 50  -atk rampup -timeout 5 -plot true
  
   // Random attack
  ./suzi -url https://example.com -req 50 -rate 5 -attack basic -timeout 5 -plot true
  

CLI Flags

Flag	Default	Description
-url	(required)	Target site or API endpoint to test
-req	10	Number of requests to send
-atk	basic	Attack type (basic, burst, rampup, random)
-method	GET	HTTP method (GET, planning to add POST)
-rate	1	Number of requests per second
-timeout	5	Request timeout in seconds
-cpus	NumCPU	Number of CPU cores to use
-email	false	Send results via email
-emailTo	"you@local.test"	Receiver email-id
-emailFrom	"Suzi <noreply@gmail.com>"	Sender email-id
-smtpHost	"localhost"	For production use "smtp.gmail.com"
-smtpPort	1025	For Production use 465 (donot use 587)
-smtp-user	os.Getenv("SMTP_USER")	Set to the email address that owns the app password (set env var for this)
-smtp-pass	os.Getenv("SMTP_PASS")	App Password generated from Gmail (set env var for this)
-smtpTLS	false	True for production
-smtp-retries	3	Email send retries
-smtp-timeout	10	Email send timeout in seconds

Email Option

• For Local testing use Docker docker run --name mailhog -d -p 8025:8025 -p 1025:1025 mailhog/mailhog. After starting the container open localhost at port 8025.
  Run the command ./suzi -url https://example.com -rate 5 -req 50 -email -atk mailAll

• For production usecase run the command carefully ./suzi -url https://example.com -rate 5 -req 50 -email -atk mailAll -email /
-emailTo "<receiver email-id> -emailFrom "Suzi <email-addr that owns app-password>" /
-smtpHost "smtp.gmail.com" -smtpPort 465 -smtpTLS true
  After that receiver should get a email like this.

Note: In Releases, you would get the binary for linux

Now The Most Fun One - Why Suzi? 🤔

• Most load testers (like JMeter or Locust) are heavy, complex, and overkill for quick checks.
• Our Suzi Offers:
  • Simple – one binary, easy flags, no config files.
  • Fast – written in Go with goroutines for concurrency.
  • Extensible – easy to add attack strategies and plotting.
  • Developer-Friendly – quick experiments, local testing, and custom benchmark.
  • Emailing - can enhance development and deployment experience.

Contributing

Contributions are always welcome! Feel free to open issues or submit pull requests for new features, enhancements, or bug fixes.

License

MIT License – free to use and modify.