Developer guide

🔷 WEBM to MKV with Go

Convert WebM videos to MKV format online for compatibility, delivery, and playback across devices and platforms.

GoREST APIWEBM → MKV

Use this guide to convert WEBM to MKV with Go, then adapt the example to your own app, backend, or processing flow.

Overview

What this guide covers

Conversion path

Use Converterer to accept or prepare a WEBM file, trigger a WEBM to MKV job, and return the output to your app or workflow.

Go example

Start with the example on this page, then adapt auth, file handling, polling, and result delivery to your environment.

Production usage

This is best suited to backend jobs, async processing, content pipelines, and repeatable conversion flows rather than one-off browser scripting.

Quick start

Get a working example in place

Code example

WEBM to MKV

package main

import (
    "bytes"
    "encoding/json"
    "fmt"
    "io"
    "mime/multipart"
    "net/http"
    "os"
)

func main() {
    body := &bytes.Buffer{}
    w := multipart.NewWriter(body)
    f, _ := os.Open("input.webm")
    fw, _ := w.CreateFormFile("input", "input.webm")
    io.Copy(fw, f)
    w.WriteField("output_format", "mkv")
    w.Close()

    req, _ := http.NewRequest(
        "POST",
        "https://api.converterer.com/convert",
        body,
    )
    req.SetBasicAuth(os.Getenv("CONVERTERER_API_KEY"), "")
    req.Header.Set("Content-Type", w.FormDataContentType())

    res, _ := http.DefaultClient.Do(req)
    var task map[string]any
    json.NewDecoder(res.Body).Decode(&task)
    fmt.Println(task["id"])
    // Result lands at <your-destination>/<id>.mkv
}

Implementation notes

What to handle in your app

API endpoint

Conversion endpoint

https://api.converterer.com/convert

Use your API key for authentication and submit the source file plus the target output format in your job request.

App responsibilities

source file upload or storage handoff
job submission and status handling
success/failure handling in your backend
download or delivery of the MKV output

Related guides