diff --git a/go.mod b/go.mod
index cab462d..34f9f53 100644
--- a/go.mod
+++ b/go.mod
@@ -8,14 +8,14 @@ require (
 	fornaxian.tech/config v0.0.0-20211108212237-6133aed90586
 	fornaxian.tech/log v0.0.0-20211102185326-552e9b1f8640
 	fornaxian.tech/pixeldrain_api_client v0.0.0-20221207191816-6872676df741
-	fornaxian.tech/util v0.0.0-20230510125310-1bc41b5fe13b
+	fornaxian.tech/util v0.0.0-20230520114728-bd827686fec7
 	github.com/julienschmidt/httprouter v1.3.0
-	github.com/microcosm-cc/bluemonday v1.0.23
+	github.com/microcosm-cc/bluemonday v1.0.24
 	github.com/russross/blackfriday/v2 v2.1.0
 )
 
 require (
-	github.com/BurntSushi/toml v1.2.1 // indirect
+	github.com/BurntSushi/toml v1.3.0 // indirect
 	github.com/aymerick/douceur v0.2.0 // indirect
 	github.com/gocql/gocql v1.4.0 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
diff --git a/go.sum b/go.sum
index 70bffeb..f217c4d 100644
--- a/go.sum
+++ b/go.sum
@@ -2,10 +2,10 @@ fornaxian.tech/config v0.0.0-20211108212237-6133aed90586 h1:/4a0Iq3cYeyTWcPHsN9p
 fornaxian.tech/config v0.0.0-20211108212237-6133aed90586/go.mod h1:ULIXF4J1DbBw4EsIPRNQDf6J3hl4P/jlihjy6UCm9FM=
 fornaxian.tech/log v0.0.0-20211102185326-552e9b1f8640 h1:UPDxJwLRCfh/cv80UMSanzmZ0jIcfS1mcd0Y06HYuLw=
 fornaxian.tech/log v0.0.0-20211102185326-552e9b1f8640/go.mod h1:sN82qMToeHhP2u3ehvrcE8y1IudRZJAZO9yG5OBYblo=
-fornaxian.tech/util v0.0.0-20230510125310-1bc41b5fe13b h1:ZJXnWqTReW9OElnanpLlpl8ElVErbYZb4cK4zjnlM1E=
-fornaxian.tech/util v0.0.0-20230510125310-1bc41b5fe13b/go.mod h1:lCmtcb4/SVt2ol55/EHDWGySY7o0ONbj97RR9CdsN4M=
-github.com/BurntSushi/toml v1.2.1 h1:9F2/+DoOYIOksmaJFPw1tGFy1eDnIJXg+UHjuD8lTak=
-github.com/BurntSushi/toml v1.2.1/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
+fornaxian.tech/util v0.0.0-20230520114728-bd827686fec7 h1:8I/BQQYO/cjREsGP+1fUqaXXM4dQ3BWfARnaUScLIec=
+fornaxian.tech/util v0.0.0-20230520114728-bd827686fec7/go.mod h1:lCmtcb4/SVt2ol55/EHDWGySY7o0ONbj97RR9CdsN4M=
+github.com/BurntSushi/toml v1.3.0 h1:Ws8e5YmnrGEHzZEzg0YvK/7COGYtTC5PbaH9oSSbgfA=
+github.com/BurntSushi/toml v1.3.0/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
 github.com/aymerick/douceur v0.2.0 h1:Mv+mAeH1Q+n9Fr+oyamOlAkUNPWPlA8PPGR0QAaYuPk=
 github.com/aymerick/douceur v0.2.0/go.mod h1:wlT5vV2O3h55X9m7iVYN0TBM0NH/MmbLnd30/FjWUq4=
 github.com/bitly/go-hostpool v0.0.0-20171023180738-a3a6125de932 h1:mXoPYz/Ul5HYEDvkta6I8/rnYM5gSdSV2tJ6XbZuEtY=
@@ -29,8 +29,8 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/microcosm-cc/bluemonday v1.0.23 h1:SMZe2IGa0NuHvnVNAZ+6B38gsTbi5e4sViiWJyDDqFY=
-github.com/microcosm-cc/bluemonday v1.0.23/go.mod h1:mN70sk7UkkF8TUr2IGBpNN0jAgStuPzlK76QuruE/z4=
+github.com/microcosm-cc/bluemonday v1.0.24 h1:NGQoPtwGVcbGkKfvyYk1yRqknzBuoMiUrO6R7uFTPlw=
+github.com/microcosm-cc/bluemonday v1.0.24/go.mod h1:ArQySAMps0790cHSkdPEJ7bGkF2VePWH773hsJNSHf8=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
diff --git a/webcontroller/file_viewer.go b/webcontroller/file_viewer.go
index f3cf2d9..dded08a 100644
--- a/webcontroller/file_viewer.go
+++ b/webcontroller/file_viewer.go
@@ -3,6 +3,7 @@ package webcontroller
 import (
 	"fmt"
 	"html/template"
+	"io"
 	"net/http"
 	"strings"
 	"time"
@@ -11,6 +12,8 @@ import (
 	"fornaxian.tech/pixeldrain_api_client/pixelapi"
 	"fornaxian.tech/util"
 	"github.com/julienschmidt/httprouter"
+	"github.com/microcosm-cc/bluemonday"
+	blackfriday "github.com/russross/blackfriday/v2"
 )
 
 func (wc *WebController) viewTokenOrBust() (t string) {
@@ -202,3 +205,39 @@ func (wc *WebController) serveListViewer(w http.ResponseWriter, r *http.Request,
 		log.Error("Error executing template file_viewer: %s", err)
 	}
 }
+
+func (wc *WebController) serveFilePreview(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
+	apiKey, _ := wc.getAPIKey(r)
+	api := wc.api.Login(apiKey).RealIP(util.RemoteAddress(r)).RealAgent(r.UserAgent())
+
+	file, err := api.GetFileInfo(p.ByName("id")) // TODO: Error handling
+	if err != nil {
+		wc.serveNotFound(w, r)
+		return
+	}
+
+	if strings.HasPrefix(file.MimeType, "text") &&
+		(strings.HasSuffix(file.Name, ".md") || strings.HasSuffix(file.Name, ".markdown")) {
+		if file.Size > 1<<22 { // Prevent out of memory errors
+			w.Write([]byte("File is too large to view online.\nPlease download and view it locally."))
+			return
+		}
+
+		body, err := api.GetFile(file.ID)
+		if err != nil {
+			log.Error("Can't download text file for preview: %s", err)
+			w.Write([]byte("An error occurred while downloading this file."))
+			return
+		}
+		defer body.Close()
+
+		bodyBytes, err := io.ReadAll(body)
+		if err != nil {
+			log.Error("Can't read text file for preview: %s", err)
+			w.Write([]byte("An error occurred while reading this file."))
+			return
+		}
+
+		w.Write(bluemonday.UGCPolicy().SanitizeBytes(blackfriday.Run(bodyBytes)))
+	}
+}
diff --git a/webcontroller/web_controller.go b/webcontroller/web_controller.go
index 0d97268..7a09cb4 100644
--- a/webcontroller/web_controller.go
+++ b/webcontroller/web_controller.go
@@ -138,6 +138,7 @@ func New(r *httprouter.Router, prefix string, conf Config) (wc *WebController) {
 		{GET, "api" /*             */, wc.serveMarkdown("api.md", handlerOpts{})},
 		{GET, "history" /*         */, wc.serveTemplate("history_cookies", handlerOpts{})},
 		{GET, "u/:id" /*           */, wc.serveFileViewer},
+		{GET, "u/:id/preview" /*   */, wc.serveFilePreview},
 		{GET, "l/:id" /*           */, wc.serveListViewer},
 		{GET, "d/*path" /*         */, wc.serveDirectory},
 		{GET, "t" /*               */, wc.serveTemplate("text_upload", handlerOpts{})},