diff --git a/.gitignore b/.gitignore
index 834b81e..528a942 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,3 +14,5 @@
 # Data generated by the app
 /cmd/def/data
 /cmd/svc/data
+data/
+main
diff --git a/README.md b/README.md
index d103c65..e5d6f85 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@ The user-friendly interface allows for straightforward secure setup and manageme
 
 ## 🏷️ Supported providers
 
-`Strato` `DDNSS` `Dynu` `Aliyun` `NoIP` `DD24` `INWX` `Infomaniak` `Hetzner`
+`Strato` `DDNSS` `Dynu` `Aliyun` `NoIP` `DD24` `INWX` `Infomaniak` `Hetzner` `Checkdomain`
 
 > **Note:** If your DynDNS provider is not listed open an issue and I will integrate it.
 
diff --git a/pkg/ddns/providers/checkdomain.go b/pkg/ddns/providers/checkdomain.go
new file mode 100644
index 0000000..1981e35
--- /dev/null
+++ b/pkg/ddns/providers/checkdomain.go
@@ -0,0 +1,177 @@
+package providers
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+
+	log "github.com/plaenkler/ddns-updater/pkg/logging"
+)
+
+const (
+	checkdomainBaseURL = "https://api.checkdomain.de/v1/dns/records"
+	checkdomainTimeout = 10 * time.Second
+)
+
+type UpdateCheckdomainRequest struct {
+	APIToken   string `json:"APIToken"`
+	Domain     string `json:"Domain"`
+	RecordName string `json:"RecordName"`
+	RecordType string `json:"RecordType"`
+	TTL        int    `json:"TTL,string"`
+}
+
+type checkdomainRecord struct {
+	ID     string `json:"id,omitempty"`
+	Name   string `json:"name"`
+	Type   string `json:"type"`
+	Value  string `json:"value"`
+	TTL    int    `json:"ttl,omitempty"`
+	Domain string `json:"domain,omitempty"`
+}
+
+type checkdomainResponse struct {
+	Records []checkdomainRecord `json:"records,omitempty"`
+	Error   string              `json:"error,omitempty"`
+	Message string              `json:"message,omitempty"`
+}
+
+func UpdateCheckdomain(request interface{}, ipAddr string) error {
+	r, ok := request.(*UpdateCheckdomainRequest)
+	if !ok {
+		return fmt.Errorf("invalid request type: %T", request)
+	}
+
+	client := &http.Client{
+		Timeout: checkdomainTimeout,
+	}
+
+	// Set default values
+	if r.RecordType == "" {
+		r.RecordType = "A"
+	}
+	if r.TTL == 0 {
+		r.TTL = 3600
+	}
+
+	// Find existing record
+	records, err := getCheckdomainRecords(client, r.APIToken, r.Domain, r.RecordName, r.RecordType)
+	if err != nil {
+		return fmt.Errorf("failed to get records: %w", err)
+	}
+
+	record := checkdomainRecord{
+		Name:   r.RecordName,
+		Type:   r.RecordType,
+		Value:  ipAddr,
+		TTL:    r.TTL,
+		Domain: r.Domain,
+	}
+
+	if len(records) > 0 {
+		// Update existing record
+		record.ID = records[0].ID
+		return updateCheckdomainRecord(client, r.APIToken, &record)
+	}
+
+	// Create new record
+	return createCheckdomainRecord(client, r.APIToken, &record)
+}
+
+func getCheckdomainRecords(client *http.Client, token, domain, name, recordType string) ([]checkdomainRecord, error) {
+	url := fmt.Sprintf("%s?domain=%s&name=%s&type=%s", checkdomainBaseURL, domain, name, recordType)
+
+	req, err := http.NewRequest(http.MethodGet, url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	req.Header.Set("Authorization", "Bearer "+token)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to send request: %w", err)
+	}
+	defer log.ErrorClose(resp.Body)
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read response: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("API returned status %d: %s", resp.StatusCode, string(body))
+	}
+
+	var response checkdomainResponse
+	if err := json.Unmarshal(body, &response); err != nil {
+		return nil, fmt.Errorf("failed to parse response: %w", err)
+	}
+
+	if response.Error != "" {
+		return nil, fmt.Errorf("API error: %s", response.Error)
+	}
+
+	return response.Records, nil
+}
+
+func createCheckdomainRecord(client *http.Client, token string, record *checkdomainRecord) error {
+	data, err := json.Marshal(record)
+	if err != nil {
+		return fmt.Errorf("failed to marshal record: %w", err)
+	}
+
+	req, err := http.NewRequest(http.MethodPost, checkdomainBaseURL, bytes.NewBuffer(data))
+	if err != nil {
+		return fmt.Errorf("failed to create request: %w", err)
+	}
+
+	req.Header.Set("Authorization", "Bearer "+token)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return fmt.Errorf("failed to send request: %w", err)
+	}
+	defer log.ErrorClose(resp.Body)
+
+	if resp.StatusCode != http.StatusCreated && resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("failed to create record, status %d: %s", resp.StatusCode, string(body))
+	}
+
+	return nil
+}
+
+func updateCheckdomainRecord(client *http.Client, token string, record *checkdomainRecord) error {
+	data, err := json.Marshal(record)
+	if err != nil {
+		return fmt.Errorf("failed to marshal record: %w", err)
+	}
+
+	url := fmt.Sprintf("%s/%s", checkdomainBaseURL, record.ID)
+	req, err := http.NewRequest(http.MethodPut, url, bytes.NewBuffer(data))
+	if err != nil {
+		return fmt.Errorf("failed to create request: %w", err)
+	}
+
+	req.Header.Set("Authorization", "Bearer "+token)
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return fmt.Errorf("failed to send request: %w", err)
+	}
+	defer log.ErrorClose(resp.Body)
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return fmt.Errorf("failed to update record, status %d: %s", resp.StatusCode, string(body))
+	}
+
+	return nil
+}
diff --git a/pkg/ddns/update.go b/pkg/ddns/update.go
index 0562323..e081e30 100644
--- a/pkg/ddns/update.go
+++ b/pkg/ddns/update.go
@@ -20,6 +20,7 @@ var updaters = map[string]provider{
 	"Dynu":         {Updater: providers.UpdateDynu, Request: providers.UpdateDynuRequest{}},
 	"Aliyun":       {Updater: providers.UpdateAliyun, Request: providers.UpdateAliyunRequest{}},
 	"AllInkl":      {Updater: providers.UpdateAllInkl, Request: providers.UpdateAllInklRequest{}},
+	"Checkdomain":  {Updater: providers.UpdateCheckdomain, Request: providers.UpdateCheckdomainRequest{}},
 	"Cloudflare":   {Updater: providers.UpdateCloudflare, Request: providers.UpdateCloudflareRequest{}},
 	"DD24":         {Updater: providers.UpdateDD24, Request: providers.UpdateDD24Request{}},
 	"DigitalOcean": {Updater: providers.UpdateDigitalOcean, Request: providers.UpdateDigitalOceanRequest{}},