diff --git a/src/models.go b/src/models.go
index b7f5310..51893d3 100644
--- a/src/models.go
+++ b/src/models.go
@@ -6,10 +6,10 @@ import "time"
 type Connection struct {
 	ID        int    `gorm:"primary_key"`
 	ClientID  string `gorm:"client_id type:varchar(70);not null;unique" json:"clientId,omitempty"`
-	APIKEY    string `gorm:"api_key type:varchar(100);not null" json:"api_key,omitempty" binding:"required"`
-	APIURL    string `gorm:"api_url type:varchar(255);not null" json:"api_url,omitempty" binding:"required,validatecrmurl"`
-	MGURL     string `gorm:"mg_url type:varchar(255);not null;" json:"mg_url,omitempty"`
-	MGToken   string `gorm:"mg_token type:varchar(100);not null;unique" json:"mg_token,omitempty"`
+	APIKEY    string `gorm:"api_key type:varchar(100);not null" json:"api_key,omitempty" binding:"required,max=100"`
+	APIURL    string `gorm:"api_url type:varchar(255);not null" json:"api_url,omitempty" binding:"required,validatecrmurl,max=255"`
+	MGURL     string `gorm:"mg_url type:varchar(255);not null;" json:"mg_url,omitempty" binding:"max=255"`
+	MGToken   string `gorm:"mg_token type:varchar(100);not null;unique" json:"mg_token,omitempty" binding:"max=100"`
 	CreatedAt time.Time
 	UpdatedAt time.Time
 	Active    bool  `json:"active,omitempty"`
@@ -21,10 +21,10 @@ type Bot struct {
 	ID                  int    `gorm:"primary_key"`
 	ConnectionID        int    `gorm:"connection_id" json:"connectionId,omitempty"`
 	Channel             uint64 `gorm:"channel;not null;unique" json:"channel,omitempty"`
-	ChannelSettingsHash string `gorm:"channel_settings_hash type:varchar(70)"`
-	Token               string `gorm:"token type:varchar(100);not null;unique" json:"token,omitempty"`
-	Name                string `gorm:"name type:varchar(40)" json:"name,omitempty"`
-	Lang                string `gorm:"lang type:varchar(2)" json:"lang,omitempty"`
+	ChannelSettingsHash string `gorm:"channel_settings_hash type:varchar(70)" binding:"max=70"`
+	Token               string `gorm:"token type:varchar(100);not null;unique" json:"token,omitempty" binding:"max=100"`
+	Name                string `gorm:"name type:varchar(40)" json:"name,omitempty" binding:"max=40"`
+	Lang                string `gorm:"lang type:varchar(2)" json:"lang,omitempty" binding:"max=2"`
 	CreatedAt           time.Time
 	UpdatedAt           time.Time
 }
@@ -33,8 +33,8 @@ type Bot struct {
 type User struct {
 	ID           int    `gorm:"primary_key"`
 	ExternalID   int    `gorm:"external_id;not null;unique"`
-	UserPhotoURL string `gorm:"user_photo_url type:varchar(255)"`
-	UserPhotoID  string `gorm:"user_photo_id type:varchar(100)"`
+	UserPhotoURL string `gorm:"user_photo_url type:varchar(255)" binding:"max=255"`
+	UserPhotoID  string `gorm:"user_photo_id type:varchar(100)" binding:"max=100"`
 	CreatedAt    time.Time
 	UpdatedAt    time.Time
 }
diff --git a/templates/form.html b/templates/form.html
index 988f6fa..708098b 100644
--- a/templates/form.html
+++ b/templates/form.html
@@ -12,12 +12,12 @@
                     <input name="clientId" type="hidden" value="{{.Conn.ClientID}}">
                     <div class="row">
                         <div class="input-field col s12">
-                            <input placeholder="CRM Url" id="api_url" name="api_url" type="text" class="validate" value="{{.Conn.APIURL}}">
+                            <input placeholder="CRM Url" id="api_url" name="api_url" type="text" class="validate" value="{{.Conn.APIURL}}" maxlength="255">
                         </div>
                     </div>
                     <div class="row">
                         <div class="input-field col s12">
-                            <input placeholder="{{.Locale.ApiKey}}" id="api_key" name="api_key" type="text" class="validate" value="{{.Conn.APIKEY}}">
+                            <input placeholder="{{.Locale.ApiKey}}" id="api_key" name="api_key" type="text" class="validate" value="{{.Conn.APIKEY}}" maxlength="100">
                         </div>
                     </div>
                     <div class="row">
@@ -40,7 +40,7 @@
                     <input name="connectionId" type="hidden" value="{{.Conn.ID}}">
                     <div class="row">
                         <div class="input-field col s12">
-                            <input placeholder="{{.Locale.TableToken}}" id="token" name="token" type="text" class="validate">
+                            <input placeholder="{{.Locale.TableToken}}" id="token" name="token" type="text" class="validate" maxlength="100">
                         </div>
                     </div>
                     <div class="row">
diff --git a/templates/home.html b/templates/home.html
index ac7b2d5..d1489fe 100644
--- a/templates/home.html
+++ b/templates/home.html
@@ -4,13 +4,13 @@
             <div id="msg"></div>
             <div class="row">
                 <div class="input-field col s12">
-                    <input placeholder="CRM Url" id="api_url" name="api_url" type="text" class="validate"
+                    <input placeholder="CRM Url" id="api_url" name="api_url" type="text" class="validate" maxlength="255"
                         {{if .Conn.APIURL}} value="{{.Conn.APIURL}}" {{end}}>
                 </div>
             </div>
             <div class="row">
                 <div class="input-field col s12">
-                    <input placeholder="{{.Locale.ApiKey}}" id="api_key" name="api_key" type="text" class="validate">
+                    <input placeholder="{{.Locale.ApiKey}}" id="api_key" name="api_key" type="text" class="validate" maxlength="100">
                 </div>
             </div>
             <div class="row">