diff --git a/cmd/web.go b/cmd/web.go
index 9f45e1a7ff7..8cd3949be19 100644
--- a/cmd/web.go
+++ b/cmd/web.go
@@ -584,7 +584,7 @@ func runWeb(ctx *cli.Context) error {
 
 		m.Group("/pulls/:index", func() {
 			m.Get("/commits", context.RepoRef(), repo.ViewPullCommits)
-			m.Get("/files", context.RepoRef(), repo.SetEditorconfigIfExists, repo.ViewPullFiles)
+			m.Get("/files", context.RepoRef(), repo.SetEditorconfigIfExists, repo.SetDiffViewStyle, repo.ViewPullFiles)
 			m.Post("/merge", reqRepoWriter, repo.MergePullRequest)
 		}, repo.MustAllowPulls)
 
@@ -592,12 +592,12 @@ func runWeb(ctx *cli.Context) error {
 			m.Get("/src/*", repo.SetEditorconfigIfExists, repo.Home)
 			m.Get("/raw/*", repo.SingleDownload)
 			m.Get("/commits/*", repo.RefCommits)
-			m.Get("/commit/:sha([a-f0-9]{7,40})$", repo.SetEditorconfigIfExists, repo.Diff)
+			m.Get("/commit/:sha([a-f0-9]{7,40})$", repo.SetEditorconfigIfExists, repo.SetDiffViewStyle, repo.Diff)
 			m.Get("/forks", repo.Forks)
 		}, context.RepoRef())
 		m.Get("/commit/:sha([a-f0-9]{7,40})\\.:ext(patch|diff)", repo.RawDiff)
 
-		m.Get("/compare/:before([a-z0-9]{40})\\.\\.\\.:after([a-z0-9]{40})", repo.CompareDiff)
+		m.Get("/compare/:before([a-z0-9]{40})\\.\\.\\.:after([a-z0-9]{40})", repo.SetEditorconfigIfExists, repo.SetDiffViewStyle, repo.CompareDiff)
 	}, ignSignIn, context.RepoAssignment(), repo.MustBeNotBare)
 	m.Group("/:username/:reponame", func() {
 		m.Get("/stars", repo.Stars)
diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index e69cf993b7e..957af42661b 100644
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -72,6 +72,8 @@ var migrations = []Migration{
 
 	// v13 -> v14:v0.9.87
 	NewMigration("set comment updated with created", setCommentUpdatedWithCreated),
+
+	NewMigration("create user column diff view style", createUserColumnDiffViewStyle),
 }
 
 // Migrate database to current version
@@ -96,7 +98,7 @@ func Migrate(x *xorm.Engine) error {
 
 	v := currentVersion.Version
 	if _MIN_DB_VER > v {
-		log.Fatal(4, `Gogs no longer supports auto-migration from your previously installed version. 
+		log.Fatal(4, `Gogs no longer supports auto-migration from your previously installed version.
 Please try to upgrade to a lower version (>= v0.6.0) first, then upgrade to current version.`)
 		return nil
 	}
diff --git a/models/migrations/v14.go b/models/migrations/v14.go
index 79c31133f43..0cdcf1005fc 100644
--- a/models/migrations/v14.go
+++ b/models/migrations/v14.go
@@ -22,3 +22,15 @@ func setCommentUpdatedWithCreated(x *xorm.Engine) (err error) {
 	}
 	return nil
 }
+
+type UserV14 struct {
+	DiffViewStyle string `xorm:"NOT NULL DEFAULT ''"`
+}
+
+func (*UserV14) TableName() string {
+	return "user"
+}
+
+func createUserColumnDiffViewStyle(x *xorm.Engine) error {
+	return x.Sync2(new(UserV14))
+}
diff --git a/models/user.go b/models/user.go
index d97ced931aa..0b6063fbc90 100644
--- a/models/user.go
+++ b/models/user.go
@@ -107,6 +107,9 @@ type User struct {
 	NumMembers  int
 	Teams       []*Team `xorm:"-"`
 	Members     []*User `xorm:"-"`
+
+	// Preferences
+	DiffViewStyle string `xorm:"NOT NULL DEFAULT ''"`
 }
 
 func (u *User) BeforeInsert() {
@@ -126,6 +129,11 @@ func (u *User) SetLastLogin() {
 	u.LastLoginUnix = time.Now().Unix()
 }
 
+func (u *User) UpdateDiffViewStyle(style string) error {
+	u.DiffViewStyle = style
+	return UpdateUser(u)
+}
+
 func (u *User) AfterSet(colName string, _ xorm.Cell) {
 	switch colName {
 	case "full_name":
diff --git a/routers/repo/commit.go b/routers/repo/commit.go
index e3170b053df..9706779ee58 100644
--- a/routers/repo/commit.go
+++ b/routers/repo/commit.go
@@ -180,7 +180,6 @@ func Diff(ctx *context.Context) {
 	}
 
 	ctx.Data["CommitID"] = commitID
-	ctx.Data["IsSplitStyle"] = ctx.Query("style") == "split"
 	ctx.Data["Username"] = userName
 	ctx.Data["Reponame"] = repoName
 	ctx.Data["IsImageFile"] = commit.IsImageFile
@@ -239,7 +238,6 @@ func CompareDiff(ctx *context.Context) {
 	}
 	commits = models.ValidateCommitsWithEmails(commits)
 
-	ctx.Data["IsSplitStyle"] = ctx.Query("style") == "split"
 	ctx.Data["CommitRepoLink"] = ctx.Repo.RepoLink
 	ctx.Data["Commits"] = commits
 	ctx.Data["CommitCount"] = commits.Len()
diff --git a/routers/repo/middlewares.go b/routers/repo/middlewares.go
index 94e007cd208..757a049ab7e 100644
--- a/routers/repo/middlewares.go
+++ b/routers/repo/middlewares.go
@@ -21,3 +21,24 @@ func SetEditorconfigIfExists(ctx *context.Context) {
 
 	ctx.Data["Editorconfig"] = ec
 }
+
+func SetDiffViewStyle(ctx *context.Context) {
+	var (
+		userStyle  = ctx.User.DiffViewStyle
+		queryStyle = ctx.Query("style")
+		style      string
+	)
+
+	if queryStyle == "unified" || queryStyle == "split" {
+		style = queryStyle
+	} else if userStyle == "unified" || userStyle == "split" {
+		style = userStyle
+	} else {
+		style = "unified"
+	}
+
+	ctx.Data["IsSplitStyle"] = style == "split"
+	if err := ctx.User.UpdateDiffViewStyle(style); err != nil {
+		ctx.Handle(500, "ErrUpdateDiffViewStyle", err)
+	}
+}
diff --git a/routers/repo/pull.go b/routers/repo/pull.go
index 83352d7f3c3..6e99dfaed09 100644
--- a/routers/repo/pull.go
+++ b/routers/repo/pull.go
@@ -367,7 +367,6 @@ func ViewPullFiles(ctx *context.Context) {
 	}
 
 	headTarget := path.Join(pull.HeadUserName, pull.HeadRepo.Name)
-	ctx.Data["IsSplitStyle"] = ctx.Query("style") == "split"
 	ctx.Data["Username"] = pull.HeadUserName
 	ctx.Data["Reponame"] = pull.HeadRepo.Name
 	ctx.Data["IsImageFile"] = commit.IsImageFile