diff --git a/custom/conf/app.example.ini b/custom/conf/app.example.ini
index 33ff7a62c56b..7cae16cd79ab 100644
--- a/custom/conf/app.example.ini
+++ b/custom/conf/app.example.ini
@@ -1029,11 +1029,16 @@ PATH =
 ;; All available themes. Allow users select personalized themes regardless of the value of `DEFAULT_THEME`.
 ;THEMES = gitea,arc-green
 ;;
-;;All available reactions users can choose on issues/prs and comments.
-;;Values can be emoji alias (:smile:) or a unicode emoji.
-;;For custom reactions, add a tightly cropped square image to public/emoji/img/reaction_name.png
+;; All available reactions users can choose on issues/prs and comments.
+;; Values can be emoji alias (:smile:) or a unicode emoji.
+;; For custom reactions, add a tightly cropped square image to public/emoji/img/reaction_name.png
 ;REACTIONS = +1, -1, laugh, hooray, confused, heart, rocket, eyes
 ;;
+;; Additional Emojis not defined in the utf8 standard
+;; By default we support gitea (:gitea:), to add more copy them to public/emoji/img/emoji_name.png and add it to this config.
+;; Dont mistake it for Reactions.
+;CUSTOM_EMOJIS = gitea
+;;
 ;; Whether the full name of the users should be shown where possible. If the full name isn't set, the username will be used.
 ;DEFAULT_SHOW_FULL_NAME = false
 ;;
diff --git a/docs/content/doc/advanced/config-cheat-sheet.en-us.md b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
index d1d47bc89301..dc3b36cb4fc1 100644
--- a/docs/content/doc/advanced/config-cheat-sheet.en-us.md
+++ b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
@@ -181,6 +181,9 @@ The following configuration set `Content-Type: application/vnd.android.package-a
 - `REACTIONS`: All available reactions users can choose on issues/prs and comments
     Values can be emoji alias (:smile:) or a unicode emoji.
     For custom reactions, add a tightly cropped square image to public/emoji/img/reaction_name.png
+- `CUSTOM_EMOJIS`: **gitea**: Additional Emojis not defined in the utf8 standard.
+    By default we support gitea (:gitea:), to add more copy them to public/emoji/img/emoji_name.png and
+    add it to this config.
 - `DEFAULT_SHOW_FULL_NAME`: **false**: Whether the full name of the users should be shown where possible. If the full name isn't set, the username will be used.
 - `SEARCH_REPO_DESCRIPTION`: **true**: Whether to search within description at repository search on explore page.
 - `USE_SERVICE_WORKER`: **true**: Whether to enable a Service Worker to cache frontend assets.
diff --git a/modules/markup/html.go b/modules/markup/html.go
index 0cc0e23b5c57..1e55629ab5dd 100644
--- a/modules/markup/html.go
+++ b/modules/markup/html.go
@@ -6,7 +6,6 @@ package markup
 
 import (
 	"bytes"
-	"fmt"
 	"io"
 	"io/ioutil"
 	"net/url"
@@ -66,7 +65,7 @@ var (
 	blackfridayExtRegex = regexp.MustCompile(`[^:]*:user-content-`)
 
 	// EmojiShortCodeRegex find emoji by alias like :smile:
-	EmojiShortCodeRegex = regexp.MustCompile(`\:[\w\+\-]+\:{1}`)
+	EmojiShortCodeRegex = regexp.MustCompile(`:[\w\+\-]+:`)
 )
 
 // CSS class for action keywords (e.g. "closes: #1")
@@ -460,17 +459,14 @@ func createEmoji(content, class, name string) *html.Node {
 	return span
 }
 
-func createCustomEmoji(alias, class string) *html.Node {
-
+func createCustomEmoji(alias string) *html.Node {
 	span := &html.Node{
 		Type: html.ElementNode,
 		Data: atom.Span.String(),
 		Attr: []html.Attribute{},
 	}
-	if class != "" {
-		span.Attr = append(span.Attr, html.Attribute{Key: "class", Val: class})
-		span.Attr = append(span.Attr, html.Attribute{Key: "aria-label", Val: alias})
-	}
+	span.Attr = append(span.Attr, html.Attribute{Key: "class", Val: "emoji"})
+	span.Attr = append(span.Attr, html.Attribute{Key: "aria-label", Val: alias})
 
 	img := &html.Node{
 		Type:     html.ElementNode,
@@ -478,10 +474,8 @@ func createCustomEmoji(alias, class string) *html.Node {
 		Data:     "img",
 		Attr:     []html.Attribute{},
 	}
-	if class != "" {
-		img.Attr = append(img.Attr, html.Attribute{Key: "alt", Val: fmt.Sprintf(`:%s:`, alias)})
-		img.Attr = append(img.Attr, html.Attribute{Key: "src", Val: fmt.Sprintf(`%s/assets/img/emoji/%s.png`, setting.StaticURLPrefix, alias)})
-	}
+	img.Attr = append(img.Attr, html.Attribute{Key: "alt", Val: ":" + alias + ":"})
+	img.Attr = append(img.Attr, html.Attribute{Key: "src", Val: setting.StaticURLPrefix + "/assets/img/emoji/" + alias + ".png"})
 
 	span.AppendChild(img)
 	return span
@@ -948,9 +942,8 @@ func emojiShortCodeProcessor(ctx *RenderContext, node *html.Node) {
 		converted := emoji.FromAlias(alias)
 		if converted == nil {
 			// check if this is a custom reaction
-			s := strings.Join(setting.UI.Reactions, " ") + "gitea"
-			if strings.Contains(s, alias) {
-				replaceContent(node, m[0], m[1], createCustomEmoji(alias, "emoji"))
+			if _, exist := setting.UI.CustomEmojisMap[alias]; exist {
+				replaceContent(node, m[0], m[1], createCustomEmoji(alias))
 				node = node.NextSibling.NextSibling
 				start = 0
 				continue
diff --git a/modules/markup/html_test.go b/modules/markup/html_test.go
index 8c3d2b5395c1..85418892ef7f 100644
--- a/modules/markup/html_test.go
+++ b/modules/markup/html_test.go
@@ -284,7 +284,18 @@ func TestRender_emoji(t *testing.T) {
 	test(
 		":gitea:",
 		`<p><span class="emoji" aria-label="gitea"><img alt=":gitea:" src="`+setting.StaticURLPrefix+`/assets/img/emoji/gitea.png"/></span></p>`)
-
+	test(
+		":custom-emoji:",
+		`<p>:custom-emoji:</p>`)
+	setting.UI.CustomEmojisMap["custom-emoji"] = ":custom-emoji:"
+	test(
+		":custom-emoji:",
+		`<p><span class="emoji" aria-label="custom-emoji"><img alt=":custom-emoji:" src="`+setting.StaticURLPrefix+`/assets/img/emoji/custom-emoji.png"/></span></p>`)
+	test(
+		"这是字符:1::+1: some🐊 \U0001f44d:custom-emoji: :gitea:",
+		`<p>这是字符:1:<span class="emoji" aria-label="thumbs up">👍</span> some<span class="emoji" aria-label="crocodile">🐊</span> `+
+			`<span class="emoji" aria-label="thumbs up">👍</span><span class="emoji" aria-label="custom-emoji"><img alt=":custom-emoji:" src="`+setting.StaticURLPrefix+`/assets/img/emoji/custom-emoji.png"/></span> `+
+			`<span class="emoji" aria-label="gitea"><img alt=":gitea:" src="`+setting.StaticURLPrefix+`/assets/img/emoji/gitea.png"/></span></p>`)
 	test(
 		"Some text with 😄 in the middle",
 		`<p>Some text with <span class="emoji" aria-label="grinning face with smiling eyes">😄</span> in the middle</p>`)
diff --git a/modules/setting/setting.go b/modules/setting/setting.go
index de167e288a47..e37b78834202 100644
--- a/modules/setting/setting.go
+++ b/modules/setting/setting.go
@@ -208,7 +208,9 @@ var (
 		DefaultTheme          string
 		Themes                []string
 		Reactions             []string
-		ReactionsMap          map[string]bool
+		ReactionsMap          map[string]bool `ini:"-"`
+		CustomEmojis          []string
+		CustomEmojisMap       map[string]string `ini:"-"`
 		SearchRepoDescription bool
 		UseServiceWorker      bool
 
@@ -256,6 +258,8 @@ var (
 		DefaultTheme:        `gitea`,
 		Themes:              []string{`gitea`, `arc-green`},
 		Reactions:           []string{`+1`, `-1`, `laugh`, `hooray`, `confused`, `heart`, `rocket`, `eyes`},
+		CustomEmojis:        []string{`gitea`},
+		CustomEmojisMap:     map[string]string{"gitea": ":gitea:"},
 		Notification: struct {
 			MinTimeout            time.Duration
 			TimeoutStep           time.Duration
@@ -983,6 +987,10 @@ func NewContext() {
 	for _, reaction := range UI.Reactions {
 		UI.ReactionsMap[reaction] = true
 	}
+	UI.CustomEmojisMap = make(map[string]string)
+	for _, emoji := range UI.CustomEmojis {
+		UI.CustomEmojisMap[emoji] = ":" + emoji + ":"
+	}
 }
 
 func parseAuthorizedPrincipalsAllow(values []string) ([]string, bool) {
diff --git a/modules/structs/settings.go b/modules/structs/settings.go
index 842b12792d1d..90c4a2107bbd 100644
--- a/modules/structs/settings.go
+++ b/modules/structs/settings.go
@@ -18,6 +18,7 @@ type GeneralRepoSettings struct {
 type GeneralUISettings struct {
 	DefaultTheme     string   `json:"default_theme"`
 	AllowedReactions []string `json:"allowed_reactions"`
+	CustomEmojis     []string `json:"custom_emojis"`
 }
 
 // GeneralAPISettings contains global api settings exposed by it
diff --git a/modules/templates/helper.go b/modules/templates/helper.go
index 83359a6ef234..f9b2dafd22a1 100644
--- a/modules/templates/helper.go
+++ b/modules/templates/helper.go
@@ -90,6 +90,9 @@ func NewFuncMap() []template.FuncMap {
 		"AllowedReactions": func() []string {
 			return setting.UI.Reactions
 		},
+		"CustomEmojis": func() map[string]string {
+			return setting.UI.CustomEmojisMap
+		},
 		"Safe":          Safe,
 		"SafeJS":        SafeJS,
 		"JSEscape":      JSEscape,
diff --git a/routers/api/v1/settings/settings.go b/routers/api/v1/settings/settings.go
index e6417e40748c..ca2d28fb8bf2 100644
--- a/routers/api/v1/settings/settings.go
+++ b/routers/api/v1/settings/settings.go
@@ -25,6 +25,7 @@ func GetGeneralUISettings(ctx *context.APIContext) {
 	ctx.JSON(http.StatusOK, api.GeneralUISettings{
 		DefaultTheme:     setting.UI.DefaultTheme,
 		AllowedReactions: setting.UI.Reactions,
+		CustomEmojis:     setting.UI.CustomEmojis,
 	})
 }
 
diff --git a/templates/base/head.tmpl b/templates/base/head.tmpl
index 10fc2bad4a02..5091eda1e996 100644
--- a/templates/base/head.tmpl
+++ b/templates/base/head.tmpl
@@ -30,6 +30,7 @@
 			AppVer: '{{AppVer}}',
 			AppSubUrl: '{{AppSubUrl}}',
 			AssetUrlPrefix: '{{AssetUrlPrefix}}',
+			CustomEmojis: {{CustomEmojis}},
 			UseServiceWorker: {{UseServiceWorker}},
 			csrf: '{{.CsrfToken}}',
 			HighlightJS: {{if .RequireHighlightJS}}true{{else}}false{{end}},
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index 7f7907b3b0c6..40dddb06a078 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -14481,6 +14481,13 @@
           },
           "x-go-name": "AllowedReactions"
         },
+        "custom_emojis": {
+          "type": "array",
+          "items": {
+            "type": "string"
+          },
+          "x-go-name": "CustomEmojis"
+        },
         "default_theme": {
           "type": "string",
           "x-go-name": "DefaultTheme"
diff --git a/web_src/js/features/emoji.js b/web_src/js/features/emoji.js
index 7a522b95fc63..254a0b5c4d92 100644
--- a/web_src/js/features/emoji.js
+++ b/web_src/js/features/emoji.js
@@ -1,8 +1,9 @@
 import emojis from '../../../assets/emoji.json';
 
 const {AssetUrlPrefix} = window.config;
+const {CustomEmojis} = window.config;
 
-const tempMap = {gitea: ':gitea:'};
+const tempMap = {...CustomEmojis};
 for (const {emoji, aliases} of emojis) {
   for (const alias of aliases || []) {
     tempMap[alias] = emoji;
@@ -23,8 +24,8 @@ for (const key of emojiKeys) {
 // retrieve HTML for given emoji name
 export function emojiHTML(name) {
   let inner;
-  if (name === 'gitea') {
-    inner = `<img alt=":${name}:" src="${AssetUrlPrefix}/img/emoji/gitea.png">`;
+  if (Object.prototype.hasOwnProperty.call(CustomEmojis, name)) {
+    inner = `<img alt=":${name}:" src="${AssetUrlPrefix}/img/emoji/${name}.png">`;
   } else {
     inner = emojiString(name);
   }