diff --git a/CHANGELOG.md b/CHANGELOG.md
index ade86966e..14fd4a477 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@
 ### Changes
 
 - [#3626](https://github.com/clojure-emacs/cider/issues/3626): `cider-ns-refresh`: jump to the relevant file/line on errors.
+- [#3628](https://github.com/clojure-emacs/cider/issues/3628): `cider-ns-refresh`: summarize errors as an overlay.
 - Bump the injected nREPL to [1.1.1](https://github.com/nrepl/nrepl/blob/v1.1.1/CHANGELOG.md#111-2024-02-20).
 - Bump the injected `cider-nrepl` to [0.46.0](https://github.com/clojure-emacs/cider-nrepl/blob/1cc9b2/CHANGELOG.md#0460-2024-0305).
   - Updates [Orchard](https://github.com/clojure-emacs/orchard/blob/v0.23.0/CHANGELOG.md#0230-2024-03-03).
diff --git a/cider-ns.el b/cider-ns.el
index 81b0cd81b..51ab0ed12 100644
--- a/cider-ns.el
+++ b/cider-ns.el
@@ -120,7 +120,8 @@ namespace-qualified function of zero arity."
 
 (defun cider-ns--present-error (error)
   "Render the `ERROR' stacktrace,
-and jump to the adequate file/line location."
+and jump to the adequate file/line location,
+presenting the error message as an overlay."
   (let* ((buf)
          (jump-args (seq-some (lambda (cause-dict) ;; a dict representing an exception cause
                                 (nrepl-dbind-response cause-dict (file-url line column)
@@ -132,7 +133,21 @@ and jump to the adequate file/line location."
                                     (list buf (cons line column)))))
                               error)))
     (when jump-args
-      (apply #'cider-jump-to jump-args))
+      (apply #'cider-jump-to jump-args)
+      (when-let ((message (seq-some (lambda (cause-dict)
+                                      (nrepl-dbind-response cause-dict (message)
+                                        message))
+                                    ;; `reverse' the causes as the first one typically is a CompilerException, which the second one is the actual exception:
+                                    (reverse error))))
+        (with-current-buffer buf
+          (let ((cider-result-use-clojure-font-lock nil)
+                (trimmed-err (funcall cider-inline-error-message-function message)))
+            (cider--display-interactive-eval-result trimmed-err
+                                                    'error
+                                                    (save-excursion
+                                                      (end-of-defun)
+                                                      (point))
+                                                    'cider-error-overlay-face)))))
     (cider--render-stacktrace-causes error)
     ;; Select the window displaying the 'culprit' buffer so that the user can immediately fix it,
     ;; as most times the displayed stacktrace doesn't need much inspection:
diff --git a/test/cider-ns-tests.el b/test/cider-ns-tests.el
index e34e0ba64..ab98499be 100644
--- a/test/cider-ns-tests.el
+++ b/test/cider-ns-tests.el
@@ -34,3 +34,172 @@
   (it "raises a user error if cider is not connected"
     (spy-on 'cider-connected-p :and-return-value nil)
     (expect (cider-ns-refresh) :to-throw 'user-error)))
+
+(defvar cider-ns-tests--sample-file-url
+  "file:test/cider_ns_tests.clj")
+
+(defvar cider-ns-tests--sample-causes
+  `((dict "class" "clojure.lang.Compiler$CompilerException" "column" 0 "compile-like" "false" "data" "{:clojure.error/phase :read-source,
+ :clojure.error/line 23,
+ :clojure.error/column 0,
+ :clojure.error/source \"gpml/handler/chat.clj\"}" "file" "gpml/handler/chat.clj" "file-url" ,cider-ns-tests--sample-file-url "line" 23 "location"
+ (dict "clojure.error/column" 0 "clojure.error/line" 23 "clojure.error/phase" "read-source" "clojure.error/source" "gpml/handler/chat.clj")
+ "message" "Syntax error reading source at (gpml/handler/chat.clj:23:0)." "path" "gpml/handler/chat.clj" "phase" "read-source" "stacktrace"
+ ((dict "class" "clojure.lang.Compiler" "file" "Compiler.java" "file-url" nil "flags"
+        ("tooling" "java")
+        "line" 7643 "method" "load" "name" "clojure.lang.Compiler/load" "type" "java")
+  (dict "class" "clojure.lang.RT" "file" "RT.java" "file-url" nil "flags"
+        ("tooling" "java")
+        "line" 381 "method" "loadResourceScript" "name" "clojure.lang.RT/loadResourceScript" "type" "java")
+  (dict "class" "clojure.lang.RT" "file" "RT.java" "file-url" nil "flags"
+        ("dup" "tooling" "java")
+        "line" 372 "method" "loadResourceScript" "name" "clojure.lang.RT/loadResourceScript" "type" "java")
+  (dict "class" "clojure.lang.RT" "file" "RT.java" "file-url" nil "flags"
+        ("tooling" "java")
+        "line" 459 "method" "load" "name" "clojure.lang.RT/load" "type" "java")
+  (dict "class" "clojure.lang.RT" "file" "RT.java" "file-url" nil "flags"
+        ("dup" "tooling" "java")
+        "line" 424 "method" "load" "name" "clojure.lang.RT/load" "type" "java")
+  (dict "class" "clojure.core$load$fn__6924" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("clj")
+        "fn" "load/fn" "line" 6167 "method" "invoke" "name" "clojure.core$load$fn__6924/invoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load")
+  (dict "class" "clojure.core$load" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("clj")
+        "fn" "load" "line" 6166 "method" "invokeStatic" "name" "clojure.core$load/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load")
+  (dict "class" "clojure.core$load" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("clj")
+        "fn" "load" "line" 6150 "method" "doInvoke" "name" "clojure.core$load/doInvoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load")
+  (dict "class" "clojure.lang.RestFn" "file" "RestFn.java" "file-url" nil "flags"
+        ("tooling" "java")
+        "line" 411 "method" "invoke" "name" "clojure.lang.RestFn/invoke" "type" "java")
+  (dict "class" "clojure.core$load_one" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("clj")
+        "fn" "load-one" "line" 5939 "method" "invokeStatic" "name" "clojure.core$load_one/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-one")
+  (dict "class" "clojure.core$load_one" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("clj")
+        "fn" "load-one" "line" 5934 "method" "invoke" "name" "clojure.core$load_one/invoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-one")
+  (dict "class" "clojure.core$load_lib$fn__6866" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("clj")
+        "fn" "load-lib/fn" "line" 5981 "method" "invoke" "name" "clojure.core$load_lib$fn__6866/invoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-lib")
+  (dict "class" "clojure.core$load_lib" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("clj")
+        "fn" "load-lib" "line" 5980 "method" "invokeStatic" "name" "clojure.core$load_lib/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-lib")
+  (dict "class" "clojure.core$load_lib" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("clj")
+        "fn" "load-lib" "line" 5959 "method" "doInvoke" "name" "clojure.core$load_lib/doInvoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-lib")
+  (dict "class" "clojure.lang.RestFn" "file" "RestFn.java" "file-url" nil "flags"
+        ("tooling" "java")
+        "line" 145 "method" "applyTo" "name" "clojure.lang.RestFn/applyTo" "type" "java")
+  (dict "class" "clojure.core$apply" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("tooling" "clj")
+        "fn" "apply" "line" 669 "method" "invokeStatic" "name" "clojure.core$apply/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/apply")
+  (dict "class" "clojure.core$load_libs" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("clj")
+        "fn" "load-libs" "line" 6022 "method" "invokeStatic" "name" "clojure.core$load_libs/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-libs")
+  (dict "class" "clojure.core$load_libs" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("clj")
+        "fn" "load-libs" "line" 6006 "method" "doInvoke" "name" "clojure.core$load_libs/doInvoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-libs")
+  (dict "class" "clojure.lang.RestFn" "file" "RestFn.java" "file-url" nil "flags"
+        ("tooling" "java")
+        "line" 140 "method" "applyTo" "name" "clojure.lang.RestFn/applyTo" "type" "java")
+  (dict "class" "clojure.core$apply" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("tooling" "clj")
+        "fn" "apply" "line" 669 "method" "invokeStatic" "name" "clojure.core$apply/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/apply")
+  (dict "class" "clojure.core$require" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("clj")
+        "fn" "require" "line" 6044 "method" "invokeStatic" "name" "clojure.core$require/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/require")
+  (dict "class" "clojure.core$require" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+        ("dup" "clj")
+        "fn" "require" "line" 6044 "method" "doInvoke" "name" "clojure.core$require/doInvoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/require")
+  (dict "class" "clojure.lang.RestFn" "file" "RestFn.java" "file-url" nil "flags"
+        ("tooling" "java")
+        "line" 424 "method" "invoke" "name" "clojure.lang.RestFn/invoke" "type" "java")))
+    (dict "class" "java.lang.RuntimeException" "compile-like" "false" "message" "Invalid token: :::a" "phase" nil "stacktrace"
+          ((dict "class" "clojure.lang.Util" "file" "Util.java" "file-url" nil "flags"
+                 ("java")
+                 "line" 221 "method" "runtimeException" "name" "clojure.lang.Util/runtimeException" "type" "java")
+           (dict "class" "clojure.lang.LispReader" "file" "LispReader.java" "file-url" nil "flags"
+                 ("java")
+                 "line" 412 "method" "interpretToken" "name" "clojure.lang.LispReader/interpretToken" "type" "java")
+           (dict "class" "clojure.lang.LispReader" "file" "LispReader.java" "file-url" nil "flags"
+                 ("java")
+                 "line" 305 "method" "read" "name" "clojure.lang.LispReader/read" "type" "java")
+           (dict "class" "clojure.lang.LispReader" "file" "LispReader.java" "file-url" nil "flags"
+                 ("dup" "java")
+                 "line" 216 "method" "read" "name" "clojure.lang.LispReader/read" "type" "java")
+           (dict "class" "clojure.lang.Compiler" "file" "Compiler.java" "file-url" nil "flags"
+                 ("tooling" "java")
+                 "line" 7631 "method" "load" "name" "clojure.lang.Compiler/load" "type" "java")
+           (dict "class" "clojure.lang.RT" "file" "RT.java" "file-url" nil "flags"
+                 ("tooling" "java")
+                 "line" 381 "method" "loadResourceScript" "name" "clojure.lang.RT/loadResourceScript" "type" "java")
+           (dict "class" "clojure.lang.RT" "file" "RT.java" "file-url" nil "flags"
+                 ("dup" "tooling" "java")
+                 "line" 372 "method" "loadResourceScript" "name" "clojure.lang.RT/loadResourceScript" "type" "java")
+           (dict "class" "clojure.lang.RT" "file" "RT.java" "file-url" nil "flags"
+                 ("tooling" "java")
+                 "line" 459 "method" "load" "name" "clojure.lang.RT/load" "type" "java")
+           (dict "class" "clojure.lang.RT" "file" "RT.java" "file-url" nil "flags"
+                 ("dup" "tooling" "java")
+                 "line" 424 "method" "load" "name" "clojure.lang.RT/load" "type" "java")
+           (dict "class" "clojure.core$load$fn__6924" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("clj")
+                 "fn" "load/fn" "line" 6167 "method" "invoke" "name" "clojure.core$load$fn__6924/invoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load")
+           (dict "class" "clojure.core$load" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("clj")
+                 "fn" "load" "line" 6166 "method" "invokeStatic" "name" "clojure.core$load/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load")
+           (dict "class" "clojure.core$load" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("clj")
+                 "fn" "load" "line" 6150 "method" "doInvoke" "name" "clojure.core$load/doInvoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load")
+           (dict "class" "clojure.lang.RestFn" "file" "RestFn.java" "file-url" nil "flags"
+                 ("tooling" "java")
+                 "line" 411 "method" "invoke" "name" "clojure.lang.RestFn/invoke" "type" "java")
+           (dict "class" "clojure.core$load_one" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("clj")
+                 "fn" "load-one" "line" 5939 "method" "invokeStatic" "name" "clojure.core$load_one/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-one")
+           (dict "class" "clojure.core$load_one" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("clj")
+                 "fn" "load-one" "line" 5934 "method" "invoke" "name" "clojure.core$load_one/invoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-one")
+           (dict "class" "clojure.core$load_lib$fn__6866" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("clj")
+                 "fn" "load-lib/fn" "line" 5981 "method" "invoke" "name" "clojure.core$load_lib$fn__6866/invoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-lib")
+           (dict "class" "clojure.core$load_lib" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("clj")
+                 "fn" "load-lib" "line" 5980 "method" "invokeStatic" "name" "clojure.core$load_lib/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-lib")
+           (dict "class" "clojure.core$load_lib" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("clj")
+                 "fn" "load-lib" "line" 5959 "method" "doInvoke" "name" "clojure.core$load_lib/doInvoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-lib")
+           (dict "class" "clojure.lang.RestFn" "file" "RestFn.java" "file-url" nil "flags"
+                 ("tooling" "java")
+                 "line" 145 "method" "applyTo" "name" "clojure.lang.RestFn/applyTo" "type" "java")
+           (dict "class" "clojure.core$apply" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("tooling" "clj")
+                 "fn" "apply" "line" 669 "method" "invokeStatic" "name" "clojure.core$apply/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/apply")
+           (dict "class" "clojure.core$load_libs" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("clj")
+                 "fn" "load-libs" "line" 6022 "method" "invokeStatic" "name" "clojure.core$load_libs/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-libs")
+           (dict "class" "clojure.core$load_libs" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("clj")
+                 "fn" "load-libs" "line" 6006 "method" "doInvoke" "name" "clojure.core$load_libs/doInvoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/load-libs")
+           (dict "class" "clojure.lang.RestFn" "file" "RestFn.java" "file-url" nil "flags"
+                 ("tooling" "java")
+                 "line" 140 "method" "applyTo" "name" "clojure.lang.RestFn/applyTo" "type" "java")
+           (dict "class" "clojure.core$apply" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("tooling" "clj")
+                 "fn" "apply" "line" 669 "method" "invokeStatic" "name" "clojure.core$apply/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/apply")
+           (dict "class" "clojure.core$require" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("clj")
+                 "fn" "require" "line" 6044 "method" "invokeStatic" "name" "clojure.core$require/invokeStatic" "ns" "clojure.core" "type" "clj" "var" "clojure.core/require")
+           (dict "class" "clojure.core$require" "file" "core.clj" "file-url" "jar:file:/Users/vemv/.m2/repository/org/clojure/clojure/1.12.900/clojure-1.12.900.jar!/clojure/core.clj" "flags"
+                 ("dup" "clj")
+                 "fn" "require" "line" 6044 "method" "doInvoke" "name" "clojure.core$require/doInvoke" "ns" "clojure.core" "type" "clj" "var" "clojure.core/require")
+           (dict "class" "clojure.lang.RestFn" "file" "RestFn.java" "file-url" nil "flags"
+                 ("tooling" "java")
+                 "line" 424 "method" "invoke" "name" "clojure.lang.RestFn/invoke" "type" "java") ))))
+
+(describe "cider-ns--present-error"
+  (it "Works without throwing errors"
+    (with-clojure-buffer ""
+      (cider-ns--present-error cider-ns-tests--sample-causes)
+      (when-let ((b (get-buffer "*cider-error*"))) ;; Clean it up for other tests
+        (kill-buffer b)))))
diff --git a/test/cider_ns_tests.clj b/test/cider_ns_tests.clj
new file mode 100644
index 000000000..66c0395a7
--- /dev/null
+++ b/test/cider_ns_tests.clj
@@ -0,0 +1,2 @@
+(ns cider-ns-tests
+  "Supports cider-ns-tests.el")