diff --git a/modules/git/grep.go b/modules/git/grep.go
index 5572bd994f..1e34f0275c 100644
--- a/modules/git/grep.go
+++ b/modules/git/grep.go
@@ -27,12 +27,20 @@ type GrepResult struct {
 	HighlightedRanges [][3]int
 }
 
+type grepMode int
+
+const (
+	FixedGrepMode grepMode = iota
+	FixedAnyGrepMode
+	RegExpGrepMode
+)
+
 type GrepOptions struct {
 	RefName           string
 	MaxResultLimit    int
 	MatchesPerFile    int
 	ContextLineNumber int
-	IsFuzzy           bool
+	Mode              grepMode
 	PathSpec          []setting.Glob
 }
 
@@ -75,11 +83,16 @@ func GrepSearch(ctx context.Context, repo *Repository, search string, opts GrepO
 	// -I skips binary files
 	cmd := NewCommand(ctx, "grep",
 		"-I", "--null", "--break", "--heading", "--column",
-		"--fixed-strings", "--line-number", "--ignore-case", "--full-name")
+		"--line-number", "--ignore-case", "--full-name")
+	if opts.Mode == RegExpGrepMode {
+		cmd.AddArguments("--perl-regexp")
+	} else {
+		cmd.AddArguments("--fixed-strings")
+	}
 	cmd.AddOptionValues("--context", fmt.Sprint(opts.ContextLineNumber))
 	cmd.AddOptionValues("--max-count", fmt.Sprint(opts.MatchesPerFile))
 	words := []string{search}
-	if opts.IsFuzzy {
+	if opts.Mode == FixedAnyGrepMode {
 		words = strings.Fields(search)
 	}
 	for _, word := range words {
diff --git a/modules/git/grep_test.go b/modules/git/grep_test.go
index 3ba7a6efcb..835f441b19 100644
--- a/modules/git/grep_test.go
+++ b/modules/git/grep_test.go
@@ -201,3 +201,34 @@ func TestGrepRefs(t *testing.T) {
 	assert.Len(t, res, 1)
 	assert.Equal(t, "A", res[0].LineCodes[0])
 }
+
+func TestGrepCanHazRegexOnDemand(t *testing.T) {
+	tmpDir := t.TempDir()
+
+	err := InitRepository(DefaultContext, tmpDir, false, Sha1ObjectFormat.Name())
+	require.NoError(t, err)
+
+	gitRepo, err := openRepositoryWithDefaultContext(tmpDir)
+	require.NoError(t, err)
+	defer gitRepo.Close()
+
+	require.NoError(t, os.WriteFile(path.Join(tmpDir, "matching"), []byte("It's a match!"), 0o666))
+	require.NoError(t, os.WriteFile(path.Join(tmpDir, "not-matching"), []byte("Orisitamatch?"), 0o666))
+
+	err = AddChanges(tmpDir, true)
+	require.NoError(t, err)
+
+	err = CommitChanges(tmpDir, CommitChangesOptions{Message: "Add fixtures for regexp test"})
+	require.NoError(t, err)
+
+	// should find nothing by default...
+	res, err := GrepSearch(context.Background(), gitRepo, "\\bmatch\\b", GrepOptions{})
+	require.NoError(t, err)
+	assert.Empty(t, res)
+
+	// ... unless configured explicitly
+	res, err = GrepSearch(context.Background(), gitRepo, "\\bmatch\\b", GrepOptions{Mode: RegExpGrepMode})
+	require.NoError(t, err)
+	assert.Len(t, res, 1)
+	assert.Equal(t, "matching", res[0].Filename)
+}
diff --git a/routers/web/repo/search.go b/routers/web/repo/search.go
index c4f9f9afd1..9a033c0f1b 100644
--- a/routers/web/repo/search.go
+++ b/routers/web/repo/search.go
@@ -17,16 +17,55 @@ import (
 
 const tplSearch base.TplName = "repo/search"
 
+type searchMode int
+
+const (
+	ExactSearchMode searchMode = iota
+	FuzzySearchMode
+	RegExpSearchMode
+)
+
+func searchModeFromString(s string) searchMode {
+	switch s {
+	case "fuzzy":
+		return FuzzySearchMode
+	case "regexp":
+		return RegExpSearchMode
+	default:
+		return ExactSearchMode
+	}
+}
+
+func (m searchMode) String() string {
+	switch m {
+	case ExactSearchMode:
+		return "exact"
+	case FuzzySearchMode:
+		return "fuzzy"
+	case RegExpSearchMode:
+		return "regexp"
+	default:
+		panic("cannot happen")
+	}
+}
+
 // Search render repository search page
 func Search(ctx *context.Context) {
 	language := ctx.FormTrim("l")
 	keyword := ctx.FormTrim("q")
 
-	isFuzzy := ctx.FormOptionalBool("fuzzy").ValueOrDefault(true)
+	mode := ExactSearchMode
+	if modeStr := ctx.FormString("mode"); len(modeStr) > 0 {
+		mode = searchModeFromString(modeStr)
+	} else if ctx.FormOptionalBool("fuzzy").ValueOrDefault(true) { // for backward compatibility in links
+		mode = FuzzySearchMode
+	}
 
 	ctx.Data["Keyword"] = keyword
 	ctx.Data["Language"] = language
-	ctx.Data["IsFuzzy"] = isFuzzy
+	ctx.Data["IsFuzzy"] = mode == FuzzySearchMode
+	ctx.Data["IsRegExp"] = mode == RegExpSearchMode
+	ctx.Data["SearchMode"] = mode.String()
 	ctx.Data["PageIsViewCode"] = true
 
 	if keyword == "" {
@@ -47,7 +86,7 @@ func Search(ctx *context.Context) {
 		total, searchResults, searchResultLanguages, err = code_indexer.PerformSearch(ctx, &code_indexer.SearchOptions{
 			RepoIDs:        []int64{ctx.Repo.Repository.ID},
 			Keyword:        keyword,
-			IsKeywordFuzzy: isFuzzy,
+			IsKeywordFuzzy: mode == FuzzySearchMode,
 			Language:       language,
 			Paginator: &db.ListOptions{
 				Page:     page,
@@ -64,11 +103,17 @@ func Search(ctx *context.Context) {
 			ctx.Data["CodeIndexerUnavailable"] = !code_indexer.IsAvailable(ctx)
 		}
 	} else {
-		res, err := git.GrepSearch(ctx, ctx.Repo.GitRepo, keyword, git.GrepOptions{
+		grepOpt := git.GrepOptions{
 			ContextLineNumber: 1,
-			IsFuzzy:           isFuzzy,
 			RefName:           ctx.Repo.RefName,
-		})
+		}
+		switch mode {
+		case FuzzySearchMode:
+			grepOpt.Mode = git.FixedAnyGrepMode
+		case RegExpSearchMode:
+			grepOpt.Mode = git.RegExpGrepMode
+		}
+		res, err := git.GrepSearch(ctx, ctx.Repo.GitRepo, keyword, grepOpt)
 		if err != nil {
 			ctx.ServerError("GrepSearch", err)
 			return
diff --git a/services/wiki/wiki.go b/services/wiki/wiki.go
index 24779d41e0..e1b37d1e7f 100644
--- a/services/wiki/wiki.go
+++ b/services/wiki/wiki.go
@@ -417,7 +417,7 @@ func SearchWikiContents(ctx context.Context, repo *repo_model.Repository, keywor
 
 	return git.GrepSearch(ctx, gitRepo, keyword, git.GrepOptions{
 		ContextLineNumber: 0,
-		IsFuzzy:           true,
+		Mode:              git.FixedAnyGrepMode,
 		RefName:           repo.GetWikiBranchName(),
 		MaxResultLimit:    10,
 		MatchesPerFile:    3,