diff --git a/services/gateway-service/internal/mediaimage/inspect.go b/services/gateway-service/internal/mediaimage/inspect.go
index 2fd98e13..ec95a138 100644
--- a/services/gateway-service/internal/mediaimage/inspect.go
+++ b/services/gateway-service/internal/mediaimage/inspect.go
@@ -10,9 +10,6 @@ import (
 	"fmt"
 	"image/jpeg"
 	"image/png"
-	"mime"
-	"path/filepath"
-	"strings"
 )
 
 const (
@@ -35,8 +32,10 @@ type Info struct {
 	SHA256      string
 }
 
-// Inspect 严格要求魔数、扩展名和 multipart Content-Type 三者一致，并拒绝 APNG 及畸形动画容器。
-func Inspect(content []byte, filename string, partContentType string) (Info, string, error) {
+// Inspect 只以完整文件字节为图片格式事实来源，并拒绝 APNG 及畸形动画容器。
+// multipart 文件名和 Content-Type 都由客户端提供，Android 相册缓存尤其可能保留错误后缀，
+// 因而调用方必须使用这里返回的规范后缀与 Content-Type 保存对象，不能再信任上传元数据。
+func Inspect(content []byte) (Info, string, error) {
 	var info Info
 	var extension string
 	switch {
@@ -82,14 +81,6 @@ func Inspect(content []byte, filename string, partContentType string) (Info, str
 	if err := validateGeometry(info); err != nil {
 		return Info{}, "", err
 	}
-	declared, _, _ := mime.ParseMediaType(strings.TrimSpace(partContentType))
-	if !strings.EqualFold(declared, info.ContentType) {
-		return Info{}, "", fmt.Errorf("file content_type does not match signature")
-	}
-	fileExtension := strings.ToLower(strings.TrimPrefix(filepath.Ext(filename), "."))
-	if fileExtension != extension && !(info.Format == "jpeg" && fileExtension == "jpeg") {
-		return Info{}, "", fmt.Errorf("filename extension does not match signature")
-	}
 	sum := sha256.Sum256(content)
 	info.SizeBytes, info.SHA256 = int64(len(content)), hex.EncodeToString(sum[:])
 	return info, extension, nil
diff --git a/services/gateway-service/internal/transport/http/appapi/avatar_media_handler.go b/services/gateway-service/internal/transport/http/appapi/avatar_media_handler.go
index 8752aa0e..f1cef9fc 100644
--- a/services/gateway-service/internal/transport/http/appapi/avatar_media_handler.go
+++ b/services/gateway-service/internal/transport/http/appapi/avatar_media_handler.go
@@ -68,7 +68,9 @@ func (h *Handler) uploadUserAvatar(writer http.ResponseWriter, request *http.Req
 		httpkit.WriteError(writer, request, http.StatusBadRequest, httpkit.CodeInvalidArgument, "file size does not match multipart metadata")
 		return
 	}
-	info, _, err := mediaimage.Inspect(content, header.Filename, header.Header.Get("Content-Type"))
+	// 文件名和 multipart Content-Type 都可能来自错误的相册缓存元数据；格式、后缀和
+	// 对象 Content-Type 只采用原始字节解析结果，避免真实 WebP/GIF 被误报为 JPEG 后拒绝。
+	info, _, err := mediaimage.Inspect(content)
 	if err != nil {
 		httpkit.WriteError(writer, request, http.StatusUnsupportedMediaType, "UNSUPPORTED_MEDIA_TYPE", err.Error())
 		return
diff --git a/services/gateway-service/internal/transport/http/roomapi/room_media_handler.go b/services/gateway-service/internal/transport/http/roomapi/room_media_handler.go
index 65e3cc99..f6d2de60 100644
--- a/services/gateway-service/internal/transport/http/roomapi/room_media_handler.go
+++ b/services/gateway-service/internal/transport/http/roomapi/room_media_handler.go
@@ -9,9 +9,7 @@ import (
 	"image/jpeg"
 	"image/png"
 	"io"
-	"mime"
 	"net/http"
-	"path/filepath"
 	"strings"
 
 	roomv1 "hyapp.local/api/proto/room/v1"
@@ -151,7 +149,9 @@ func (h *Handler) uploadRoomMedia(writer http.ResponseWriter, request *http.Requ
 		httpkit.WriteError(writer, request, http.StatusBadRequest, httpkit.CodeInvalidArgument, "file size does not match multipart metadata")
 		return
 	}
-	media, _, err := inspectRoomImage(content, header.Filename, header.Header.Get("Content-Type"))
+	// 相册缓存文件名和 multipart Content-Type 不可信；格式、后缀和对象 Content-Type
+	// 全部从原始字节解析，确保 WebP/GIF 即使带着 JPG 元数据也能按真实类型保存。
+	media, _, err := inspectRoomImage(content)
 	if err != nil {
 		httpkit.WriteError(writer, request, http.StatusUnsupportedMediaType, "UNSUPPORTED_MEDIA_TYPE", err.Error())
 		return
@@ -237,7 +237,7 @@ func (h *Handler) uploadRoomMedia(writer http.ResponseWriter, request *http.Requ
 	})
 }
 
-func inspectRoomImage(content []byte, filename string, partContentType string) (roomMediaData, string, error) {
+func inspectRoomImage(content []byte) (roomMediaData, string, error) {
 	var data roomMediaData
 	var extension string
 	switch {
@@ -280,15 +280,6 @@ func inspectRoomImage(content []byte, filename string, partContentType string) (
 	default:
 		return data, "", fmt.Errorf("only jpeg, png, gif and webp are supported")
 	}
-	declared, _, _ := mime.ParseMediaType(strings.TrimSpace(partContentType))
-	if !strings.EqualFold(declared, data.ContentType) {
-		return roomMediaData{}, "", fmt.Errorf("file content_type does not match signature")
-	}
-	fileExtension := strings.ToLower(strings.TrimPrefix(filepath.Ext(filename), "."))
-	validExtension := fileExtension == extension || (data.Format == "jpeg" && fileExtension == "jpeg")
-	if !validExtension {
-		return roomMediaData{}, "", fmt.Errorf("filename extension does not match signature")
-	}
 	sum := sha256.Sum256(content)
 	data.SizeBytes, data.SHA256, data.Status = int64(len(content)), hex.EncodeToString(sum[:]), "active"
 	return data, extension, nil