diff --git a/config/config.go b/config/config.go
index 4c380c3..ce8664a 100644
--- a/config/config.go
+++ b/config/config.go
@@ -3,8 +3,6 @@ package config
 
 import (
 	"context"
-	"errors"
-	"fmt"
 	"log"
 	"net/url"
 	"strings"
@@ -15,6 +13,7 @@ import (
 	// "github.com/goware/urlx"
 	"github.com/sethvargo/go-envconfig"
 
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 	"codeberg.org/vnpower/pixivfe/v2/server/token_manager"
 )
 
@@ -102,10 +101,10 @@ func validateURL(urlString string, urlType string) (*url.URL, error) {
 	}
 	// Ensure both scheme and host are present in the URL
 	if parsedURL.Scheme == "" || parsedURL.Host == "" {
-		return nil, fmt.Errorf("%s URL is invalid: %s. Please specify a complete URL with scheme and host, e.g. https://example.com", urlType, urlString)
+		return nil, i18n.Errorf("%s URL is invalid: %s. Please specify a complete URL with scheme and host, e.g. https://example.com", urlType, urlString)
 	}
 	if strings.HasSuffix(parsedURL.Path, "/") {
-		return nil, fmt.Errorf("%s URL path (%s) cannot end in /: %s. PixivFE does not support this now", urlType, parsedURL.Path, urlString)
+		return nil, i18n.Errorf("%s URL path (%s) cannot end in /: %s. PixivFE does not support this now", urlType, parsedURL.Path, urlString)
 	}
 	return parsedURL, nil
 }
@@ -152,13 +151,13 @@ func (s *ServerConfig) LoadConfig() error {
 
 	if s.Port == "" && s.UnixSocket == "" {
 		log.Fatalln("Either PIXIVFE_PORT or PIXIVFE_UNIXSOCKET has to be set.")
-		return errors.New("Either PIXIVFE_PORT or PIXIVFE_UNIXSOCKET has to be set")
+		return i18n.Error("Either PIXIVFE_PORT or PIXIVFE_UNIXSOCKET has to be set")
 	}
 
 	// a check for tokens
 	if len(s.Token) < 1 {
 		log.Fatalln("PIXIVFE_TOKEN has to be set. Visit https://pixivfe-docs.pages.dev/hosting/hosting-pixivfe for more details.")
-		return errors.New("PIXIVFE_TOKEN has to be set. Visit https://pixivfe-docs.pages.dev/hosting/hosting-pixivfe for more details")
+		return i18n.Error("PIXIVFE_TOKEN has to be set. Visit https://pixivfe-docs.pages.dev/hosting/hosting-pixivfe for more details")
 	}
 
 	// Validate proxy server URL
diff --git a/core/discovery.go b/core/discovery.go
index 7cb2492..4cea802 100644
--- a/core/discovery.go
+++ b/core/discovery.go
@@ -1,12 +1,13 @@
 package core
 
 import (
-	"fmt"
+	"net/http"
 
-	"codeberg.org/vnpower/pixivfe/v2/server/session"
 	"github.com/goccy/go-json"
 	"github.com/tidwall/gjson"
-	"net/http"
+
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
+	"codeberg.org/vnpower/pixivfe/v2/server/session"
 )
 
 func GetDiscoveryArtwork(r *http.Request, mode string) ([]ArtworkBrief, error) {
@@ -22,7 +23,7 @@ func GetDiscoveryArtwork(r *http.Request, mode string) ([]ArtworkBrief, error) {
 	}
 	resp = session.ProxyImageUrl(r, resp)
 	if !gjson.Valid(resp) {
-		return nil, fmt.Errorf("Invalid JSON: %v", resp)
+		return nil, i18n.Errorf("Invalid JSON: %v", resp)
 	}
 	data := gjson.Get(resp, "thumbnails.illust").String()
 
@@ -47,7 +48,7 @@ func GetDiscoveryNovels(r *http.Request, mode string) ([]NovelBrief, error) {
 	}
 	resp = session.ProxyImageUrl(r, resp)
 	if !gjson.Valid(resp) {
-		return nil, fmt.Errorf("Invalid JSON: %v", resp)
+		return nil, i18n.Errorf("Invalid JSON: %v", resp)
 	}
 	data := gjson.Get(resp, "thumbnails.novel").String()
 
diff --git a/core/index.go b/core/index.go
index 48a0e9b..db96586 100644
--- a/core/index.go
+++ b/core/index.go
@@ -2,11 +2,13 @@ package core
 
 import (
 	"fmt"
+	"net/http"
 
-	"codeberg.org/vnpower/pixivfe/v2/server/session"
 	"github.com/goccy/go-json"
 	"github.com/tidwall/gjson"
-	"net/http"
+
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
+	"codeberg.org/vnpower/pixivfe/v2/server/session"
 )
 
 type Pixivision struct {
@@ -59,7 +61,7 @@ func GetLanding(r *http.Request, mode string) (*LandingArtworks, error) {
 	resp = session.ProxyImageUrl(r, resp)
 
 	if !gjson.Valid(resp) {
-		return nil, fmt.Errorf("Invalid JSON: %v", resp)
+		return nil, i18n.Errorf("Invalid JSON: %v", resp)
 	}
 
 	artworks := map[string]ArtworkBrief{}
diff --git a/core/pixivision.go b/core/pixivision.go
index f6ab2df..4cf4123 100644
--- a/core/pixivision.go
+++ b/core/pixivision.go
@@ -1,7 +1,6 @@
 package core
 
 import (
-	"errors"
 	"fmt"
 	"html"
 	"io"
@@ -10,6 +9,8 @@ import (
 	"time"
 
 	"github.com/PuerkitoBio/goquery"
+
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 )
 
 const PixivDatetimeLayout = "2006-01-02"
@@ -37,7 +38,7 @@ func executeRequest(req *http.Request) (*http.Response, error) {
 	client := http.Client{Timeout: 60 * time.Second}
 	resp, err := client.Do(req)
 	if resp.StatusCode != 200 {
-		return nil, errors.New("Pixivision: Page not found")
+		return nil, i18n.Error("Pixivision: Page not found")
 	}
 	if err != nil {
 		return nil, err
@@ -126,7 +127,7 @@ func PixivisionGetHomepage(r *http.Request, page string, lang ...string) ([]Pixi
 	}
 
 	if resp.StatusCode == 404 {
-		return articles, errors.New("We couldn't find the page you're looking for")
+		return articles, i18n.Error("We couldn't find the page you're looking for")
 	}
 
 	doc, err := goquery.NewDocumentFromReader(resp.Body)
diff --git a/core/requests.go b/core/requests.go
index bc2e598..5ab1bb6 100644
--- a/core/requests.go
+++ b/core/requests.go
@@ -4,12 +4,12 @@ import (
 	"bytes"
 	"context"
 	"errors"
-	"fmt"
 	"io"
 	"net/http"
 	"time"
 
-	config "codeberg.org/vnpower/pixivfe/v2/config"
+	"codeberg.org/vnpower/pixivfe/v2/config"
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 	"codeberg.org/vnpower/pixivfe/v2/server/audit"
 	"codeberg.org/vnpower/pixivfe/v2/server/request_context"
 	"codeberg.org/vnpower/pixivfe/v2/server/token_manager"
@@ -65,7 +65,7 @@ func retryRequest(ctx context.Context, reqFunc func(context.Context, string) (*r
 
 		if token == nil && !isPost {
 			tokenManager.ResetAllTokens()
-			return nil, fmt.Errorf("All tokens (%d) are timed out, resetting all tokens to their initial good state.\n"+
+			return nil, i18n.Errorf("All tokens (%d) are timed out, resetting all tokens to their initial good state.\n"+
 				"Consider providing additional tokens in PIXIVFE_TOKEN or reviewing API request level backoff configuration.\n"+
 				"Please refer the following documentation for additional information:\n"+
 				"- https://pixivfe-docs.pages.dev/hosting/obtaining-pixivfe-token/\n"+
@@ -118,7 +118,7 @@ func retryRequest(ctx context.Context, reqFunc func(context.Context, string) (*r
 			}, nil
 		}
 
-		lastErr = fmt.Errorf("HTTP status code: %d", resp.StatusCode)
+		lastErr = i18n.Errorf("HTTP status code: %d", resp.StatusCode)
 
 		if userToken == "" && !isPost {
 			tokenManager.MarkTokenStatus(token, token_manager.TimedOut)
@@ -132,7 +132,7 @@ func retryRequest(ctx context.Context, reqFunc func(context.Context, string) (*r
 		}
 	}
 
-	return nil, fmt.Errorf("Max retries reached. Last error: %v", lastErr)
+	return nil, i18n.Errorf("Max retries reached. Last error: %v", lastErr)
 }
 
 // API_GET performs a GET request to the Pixiv API with automatic retries
@@ -161,13 +161,13 @@ func API_GET_UnwrapJson(ctx context.Context, url string, userToken string) (stri
 	}
 
 	if !gjson.Valid(resp.Body) {
-		return "", fmt.Errorf("Invalid JSON: %v", resp.Body)
+		return "", i18n.Errorf("Invalid JSON: %v", resp.Body)
 	}
 
 	err2 := gjson.Get(resp.Body, "error")
 
 	if !err2.Exists() {
-		return "", errors.New("Incompatible request body")
+		return "", i18n.Error("Incompatible request body")
 	}
 
 	if err2.Bool() {
@@ -180,7 +180,7 @@ func API_GET_UnwrapJson(ctx context.Context, url string, userToken string) (stri
 // API_POST performs a POST request to the Pixiv API with automatic retries
 func API_POST(ctx context.Context, url, payload, userToken, csrf string, isJSON bool) error {
 	if userToken == "" {
-		return errors.New("userToken is required for POST requests")
+		return i18n.Error("userToken is required for POST requests")
 	}
 
 	_, err := retryRequest(ctx, func(ctx context.Context, token string) (*retryablehttp.Request, error) {
@@ -236,7 +236,7 @@ func proxyWorker(jobs <-chan ProxyJob) {
 func processProxyJob(job ProxyJob) error {
 	resp, err := utils.HttpClient.Do(job.Request)
 	if err != nil {
-		return fmt.Errorf("failed to process request: %w", err)
+		return i18n.Errorf("failed to process request: %w", err)
 	}
 	defer resp.Body.Close()
 
@@ -252,7 +252,7 @@ func processProxyJob(job ProxyJob) error {
 	// Copy the body from the response to the original writer
 	_, err = io.Copy(job.Response, resp.Body)
 	if err != nil {
-		return fmt.Errorf("failed to copy response body: %w", err)
+		return i18n.Errorf("failed to copy response body: %w", err)
 	}
 
 	return nil
diff --git a/core/user.go b/core/user.go
index 257bd0b..5e4edf7 100644
--- a/core/user.go
+++ b/core/user.go
@@ -1,14 +1,15 @@
 package core
 
 import (
-	"errors"
 	"fmt"
 	"math"
 	"sort"
 
+	"net/http"
+
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 	"codeberg.org/vnpower/pixivfe/v2/server/session"
 	"github.com/goccy/go-json"
-	"net/http"
 )
 
 // pixivfe internal data type. not used by pixiv.
@@ -30,7 +31,7 @@ func (s UserArtCategory) Validate() error {
 		s != UserArt_Manga &&
 		s != UserArt_Bookmarks &&
 		s != UserArt_Novel {
-		return fmt.Errorf("Invalid work category: %#v. "+`Only "%s", "%s", "%s", "%s", "%s" and "%s" are available`, s, UserArt_Any, UserArt_AnyAlt, UserArt_Illustration, UserArt_Manga, UserArt_Bookmarks, UserArt_Novel)
+		return i18n.Errorf("Invalid work category: %#v. "+`Only "%s", "%s", "%s", "%s", "%s" and "%s" are available`, s, UserArt_Any, UserArt_AnyAlt, UserArt_Illustration, UserArt_Manga, UserArt_Bookmarks, UserArt_Novel)
 	} else {
 		return nil
 	}
@@ -234,7 +235,7 @@ func GetUserArtworksID(r *http.Request, id string, category UserArtCategory, pag
 	worksPerPage := 30.0
 
 	if page < 1 || float64(page) > math.Ceil(worksNumber/worksPerPage)+1.0 {
-		return "", -1, errors.New("No page available.")
+		return "", -1, i18n.Error("No page available.")
 	}
 
 	start := (page - 1) * int(worksPerPage)
diff --git a/i18n/localize_errors.go b/i18n/localize_errors.go
new file mode 100644
index 0000000..932c5d2
--- /dev/null
+++ b/i18n/localize_errors.go
@@ -0,0 +1,16 @@
+package i18n
+
+import (
+	"errors"
+	"fmt"
+)
+
+func Error(text string) error {
+	text = Lookup(text)
+	return errors.New(text)
+}
+
+func Errorf(format string, a ...any) error {
+	format = Lookup(format)
+	return fmt.Errorf(format, a...)
+}
diff --git a/i18n/lookup.go b/i18n/lookup.go
new file mode 100644
index 0000000..e7d4af0
--- /dev/null
+++ b/i18n/lookup.go
@@ -0,0 +1,6 @@
+package i18n
+
+func Lookup(text string) string {
+	// todo
+	return text
+}
diff --git a/main.go b/main.go
index 39596e6..3a6284a 100644
--- a/main.go
+++ b/main.go
@@ -2,7 +2,6 @@ package main
 
 import (
 	"context"
-	"fmt"
 	"log"
 	"net"
 	"net/http"
@@ -14,6 +13,7 @@ import (
 	"time"
 
 	"codeberg.org/vnpower/pixivfe/v2/config"
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 	"codeberg.org/vnpower/pixivfe/v2/server/audit"
 	"codeberg.org/vnpower/pixivfe/v2/server/middleware"
 	"codeberg.org/vnpower/pixivfe/v2/server/proxy_checker"
@@ -86,7 +86,7 @@ func run_sass() {
 	runtime.LockOSThread() // Go quirk https://github.com/golang/go/issues/27505
 	err := cmd.Run()
 	if err != nil {
-		log.Print(fmt.Errorf("when running sass: %w", err))
+		log.Print(i18n.Errorf("when running sass: %w", err), err)
 	}
 }
 
diff --git a/semgrep.yml b/semgrep.yml
index 7b029a9..ac5b7f0 100644
--- a/semgrep.yml
+++ b/semgrep.yml
@@ -164,15 +164,23 @@ rules:
   - pattern-not-inside: |
       ...
       defer $RESP.Body.Close()
-- id: "13"
-  message: "error string"
+- id: "13a"
+  message: "untranslated errors.New"
   languages: [go]
-  severity: INFO
-  pattern-either:
-  - pattern: |
-      errors.New(...)
-  - pattern: |
-      fmt.Errorf(...)
+  severity: ERROR
+  pattern: |
+    errors.New("$MSG")
+  fix: |
+    i18n.Error("$MSG")
+- id: "13b"
+  message: "untranslated fmt.Errorf"
+  languages: [go]
+  severity: ERROR
+  pattern: |
+    fmt.Errorf("$MSG", $...ARGS)
+  fix: |
+    i18n.Errorf("$MSG", $...ARGS)
+
 - id: "14"
   message: "non-global regexp.MustCompile"
   languages: [go]
diff --git a/server/audit/audit_init.go b/server/audit/audit_init.go
index acd80a3..5b27400 100644
--- a/server/audit/audit_init.go
+++ b/server/audit/audit_init.go
@@ -1,11 +1,11 @@
 package audit
 
 import (
-	"fmt"
 	"log"
 	"os"
 
 	"codeberg.org/vnpower/pixivfe/v2/config"
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 )
 
 var optionSaveResponse bool
@@ -26,7 +26,7 @@ func Init(saveResponse bool) error {
 
 	if err := os.MkdirAll(savePath, 0o700); err != nil {
 		log.Printf("Error creating response save directory: %v", err)
-		return fmt.Errorf("failed to create response save directory: %w", err)
+		return i18n.Errorf("failed to create response save directory: %w", err)
 	}
 
 	return nil
diff --git a/server/audit/audit_log.go b/server/audit/audit_log.go
index 2f252ab..958d5fb 100644
--- a/server/audit/audit_log.go
+++ b/server/audit/audit_log.go
@@ -3,14 +3,15 @@
 package audit
 
 import (
-	"fmt"
 	"log"
 	"os"
 	"path"
 	"time"
 
-	"codeberg.org/vnpower/pixivfe/v2/config"
 	"github.com/oklog/ulid/v2"
+
+	"codeberg.org/vnpower/pixivfe/v2/config"
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 )
 
 // Logger is a custom logger with no timestamp prefix, as we control the timestamps in our log messages.
@@ -77,7 +78,7 @@ func writeResponseBodyToFile(body string) (string, error) {
 	// Write the body to the file with read/write permissions for the owner only
 	err := os.WriteFile(filename, []byte(body), 0o600)
 	if err != nil {
-		return "", fmt.Errorf("failed to write response body to file %s: %w", filename, err)
+		return "", i18n.Errorf("failed to write response body to file %s: %w", filename, err)
 	}
 	log.Printf("Successfully wrote response body to file: %s", filename)
 	return filename, nil
diff --git a/server/middleware/router.go b/server/middleware/router.go
index 8f33625..e8ee504 100644
--- a/server/middleware/router.go
+++ b/server/middleware/router.go
@@ -1,12 +1,13 @@
 package middleware
 
 import (
-	"errors"
 	"net/http"
 	"strings"
 
-	"codeberg.org/vnpower/pixivfe/v2/server/routes"
 	"github.com/gorilla/mux"
+
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
+	"codeberg.org/vnpower/pixivfe/v2/server/routes"
 )
 
 // handleStripPrefix is a utility function that combines path prefix matching with
@@ -129,7 +130,7 @@ func DefineRoutes() *mux.Router {
 	// Fallback route (if nothing else matches)
 	// This ensures that a proper HTTP 404 error is returned for undefined routes
 	router.NewRoute().HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		routes.ErrorPage(w, r, errors.New("Route not found"), http.StatusNotFound)
+		routes.ErrorPage(w, r, i18n.Error("Route not found"), http.StatusNotFound)
 	})
 
 	return router
diff --git a/server/routes/actions.go b/server/routes/actions.go
index 470911c..30d9392 100644
--- a/server/routes/actions.go
+++ b/server/routes/actions.go
@@ -1,11 +1,11 @@
 package routes
 
 import (
-	"errors"
 	"fmt"
 	"net/http"
 
 	"codeberg.org/vnpower/pixivfe/v2/core"
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 	"codeberg.org/vnpower/pixivfe/v2/server/session"
 	"codeberg.org/vnpower/pixivfe/v2/server/utils"
 )
@@ -20,7 +20,7 @@ func AddBookmarkRoute(w http.ResponseWriter, r *http.Request) error {
 
 	id := GetPathVar(r, "id")
 	if id == "" {
-		return errors.New("No ID provided.")
+		return i18n.Error("No ID provided.")
 	}
 
 	URL := "https://www.pixiv.net/ajax/illusts/bookmarks/add"
@@ -48,7 +48,7 @@ func DeleteBookmarkRoute(w http.ResponseWriter, r *http.Request) error {
 
 	id := GetPathVar(r, "id")
 	if id == "" {
-		return errors.New("No ID provided.")
+		return i18n.Error("No ID provided.")
 	}
 
 	// You can't unlike
@@ -72,7 +72,7 @@ func LikeRoute(w http.ResponseWriter, r *http.Request) error {
 
 	id := GetPathVar(r, "id")
 	if id == "" {
-		return errors.New("No ID provided.")
+		return i18n.Error("No ID provided.")
 	}
 
 	URL := "https://www.pixiv.net/ajax/illusts/like"
diff --git a/server/routes/artwork.go b/server/routes/artwork.go
index 7a76bb8..1aa2924 100644
--- a/server/routes/artwork.go
+++ b/server/routes/artwork.go
@@ -2,16 +2,17 @@ package routes
 
 import (
 	"fmt"
+	"net/http"
 	"strconv"
 
 	"codeberg.org/vnpower/pixivfe/v2/core"
-	"net/http"
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 )
 
 func ArtworkPage(w http.ResponseWriter, r *http.Request) error {
 	id := GetPathVar(r, "id")
 	if _, err := strconv.Atoi(id); err != nil {
-		return fmt.Errorf("Invalid ID: %s", id)
+		return i18n.Errorf("Invalid ID: %s", id)
 	}
 
 	illust, err := core.GetArtworkByID(r, id, true)
diff --git a/server/routes/artworkMulti.go b/server/routes/artworkMulti.go
index 91008b3..da5b307 100644
--- a/server/routes/artworkMulti.go
+++ b/server/routes/artworkMulti.go
@@ -2,12 +2,13 @@ package routes
 
 import (
 	"fmt"
+	"net/http"
 	"strconv"
 	"strings"
 	"sync"
 
 	"codeberg.org/vnpower/pixivfe/v2/core"
-	"net/http"
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 )
 
 func ArtworkMultiPage(w http.ResponseWriter, r *http.Request) error {
@@ -26,7 +27,7 @@ func ArtworkMultiPage(w http.ResponseWriter, r *http.Request) error {
 	var err_global error = nil
 	for i, id := range ids {
 		if _, err := strconv.Atoi(id); err != nil {
-			err_global = fmt.Errorf("Invalid ID: %s", id)
+			err_global = i18n.Errorf("Invalid ID: %s", id)
 			break
 		}
 
diff --git a/server/routes/novel.go b/server/routes/novel.go
index 188d393..47b34fc 100644
--- a/server/routes/novel.go
+++ b/server/routes/novel.go
@@ -2,19 +2,19 @@ package routes
 
 import (
 	"fmt"
+	"net/http"
 	"strconv"
 	"strings"
 
-	"net/http"
-
 	"codeberg.org/vnpower/pixivfe/v2/core"
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 	"codeberg.org/vnpower/pixivfe/v2/server/session"
 )
 
 func NovelPage(w http.ResponseWriter, r *http.Request) error {
 	id := GetPathVar(r, "id")
 	if _, err := strconv.Atoi(id); err != nil {
-		return fmt.Errorf("Invalid ID: %s", id)
+		return i18n.Errorf("Invalid ID: %s", id)
 	}
 
 	novel, err := core.GetNovelByID(r, id)
diff --git a/server/routes/novelseries.go b/server/routes/novelseries.go
index 238d606..f30435f 100644
--- a/server/routes/novelseries.go
+++ b/server/routes/novelseries.go
@@ -8,12 +8,13 @@ import (
 	"net/http"
 
 	"codeberg.org/vnpower/pixivfe/v2/core"
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 )
 
 func NovelSeriesPage(w http.ResponseWriter, r *http.Request) error {
 	id := GetPathVar(r, "id")
 	if _, err := strconv.Atoi(id); err != nil {
-		return fmt.Errorf("Invalid ID: %s", id)
+		return i18n.Errorf("Invalid ID: %s", id)
 	}
 
 	series, err := core.GetNovelSeriesByID(r, id)
@@ -28,7 +29,7 @@ func NovelSeriesPage(w http.ResponseWriter, r *http.Request) error {
 	page := GetQueryParam(r, "p", "1")
 	pageNum, err := strconv.Atoi(page)
 	if err != nil || pageNum < 1 || pageNum > pageLimit {
-		return fmt.Errorf("Invalid Page")
+		return i18n.Errorf("Invalid Page Number: %d", pageNum)
 	}
 
 	// TODO should use token only if R-18/R-18G
diff --git a/server/routes/settings.go b/server/routes/settings.go
index 3c03af4..a3ce5cc 100644
--- a/server/routes/settings.go
+++ b/server/routes/settings.go
@@ -1,8 +1,6 @@
 package routes
 
 import (
-	"errors"
-	"fmt"
 	"net/http"
 	"regexp"
 	"slices"
@@ -10,6 +8,7 @@ import (
 
 	"codeberg.org/vnpower/pixivfe/v2/config"
 	"codeberg.org/vnpower/pixivfe/v2/core"
+	"codeberg.org/vnpower/pixivfe/v2/i18n"
 	"codeberg.org/vnpower/pixivfe/v2/server/proxy_checker"
 	"codeberg.org/vnpower/pixivfe/v2/server/session"
 	"codeberg.org/vnpower/pixivfe/v2/server/utils"
@@ -24,7 +23,7 @@ func setToken(w http.ResponseWriter, r *http.Request) error {
 
 		_, err := core.API_GET_UnwrapJson(r.Context(), URL, token)
 		if err != nil {
-			return errors.New("Cannot authorize with supplied token.")
+			return i18n.Error("Cannot authorize with supplied token.")
 		}
 
 		// Make a test request to verify the token.
@@ -35,14 +34,14 @@ func setToken(w http.ResponseWriter, r *http.Request) error {
 		}
 
 		if resp.StatusCode != 200 {
-			return errors.New("Cannot authorize with supplied token.")
+			return i18n.Error("Cannot authorize with supplied token.")
 		}
 
 		// CSRF token
 		csrf := r_csrf.FindStringSubmatch(resp.Body)[1]
 
 		if csrf == "" {
-			return errors.New("Cannot authorize with supplied token.")
+			return i18n.Error("Cannot authorize with supplied token.")
 		}
 
 		// Set the token
@@ -51,7 +50,7 @@ func setToken(w http.ResponseWriter, r *http.Request) error {
 
 		return nil
 	}
-	return errors.New("You submitted an empty/invalid form.")
+	return i18n.Error("You submitted an empty/invalid form.")
 }
 
 func setImageServer(w http.ResponseWriter, r *http.Request) error {
@@ -127,7 +126,7 @@ func setCookie(w http.ResponseWriter, r *http.Request) error {
 			return nil
 		}
 	}
-	return fmt.Errorf("Invalid Cookie Name: %s", key)
+	return i18n.Errorf("Invalid Cookie Name: %s", key)
 }
 
 func setRawCookie(w http.ResponseWriter, r *http.Request) error {
@@ -189,7 +188,7 @@ func SettingsPost(w http.ResponseWriter, r *http.Request) error {
 	case "raw":
 		err = setRawCookie(w, r)
 	default:
-		err = errors.New("No such setting is available.")
+		err = i18n.Error("No such setting is available.")
 	}
 
 	if err != nil {