diff --git a/Cargo.lock b/Cargo.lock
index ee7b3349..2ea5f8bf 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -380,6 +380,22 @@ dependencies = [
  "windows-sys 0.45.0",
 ]
 
+[[package]]
+name = "console"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a50aab2529019abfabfa93f1e6c41ef392f91fbf179b347a7e96abb524884a08"
+dependencies = [
+ "encode_unicode",
+ "lazy_static",
+ "libc",
+ "regex",
+ "terminal_size",
+ "unicode-width",
+ "winapi",
+ "winapi-util",
+]
+
 [[package]]
 name = "console"
 version = "0.15.8"
@@ -496,12 +512,18 @@ version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "658bce805d770f407bc62102fca7c2c64ceef2fbcb2b8bd19d2765ce093980de"
 dependencies = [
- "console",
+ "console 0.15.8",
  "shell-words",
  "thiserror",
  "zeroize",
 ]
 
+[[package]]
+name = "difflib"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6184e33543162437515c2e2b48714794e37845ec9851711914eec9d308f6ebe8"
+
 [[package]]
 name = "digest"
 version = "0.10.7"
@@ -1155,6 +1177,18 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "json-structural-diff"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "25c7940d3c84d2079306c176c7b2b37622b6bc5e43fbd1541b1e4a4e1fd02045"
+dependencies = [
+ "console 0.13.0",
+ "difflib",
+ "regex",
+ "serde_json",
+]
+
 [[package]]
 name = "kqueue"
 version = "1.0.8"
@@ -1338,7 +1372,7 @@ dependencies = [
  "chrono",
  "clap",
  "colored",
- "console",
+ "console 0.15.8",
  "ctrlc",
  "dialoguer",
  "dissimilar",
@@ -1351,6 +1385,7 @@ dependencies = [
  "hyper-staticfile",
  "hyper-util",
  "indexmap",
+ "json-structural-diff",
  "line-index",
  "log",
  "mooncake",
@@ -2264,6 +2299,16 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "terminal_size"
+version = "0.1.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "633c1a546cee861a1a6d0dc69ebeca693bf4296661ba7852b9d21d159e0506df"
+dependencies = [
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "test-log"
 version = "0.2.16"
diff --git a/crates/moonbuild/Cargo.toml b/crates/moonbuild/Cargo.toml
index d35a5603..9779c847 100644
--- a/crates/moonbuild/Cargo.toml
+++ b/crates/moonbuild/Cargo.toml
@@ -60,6 +60,7 @@ semver.workspace = true
 chrono.workspace = true
 zip.workspace = true
 thiserror.workspace = true
+json-structural-diff = { version = "0.1.0", features = ["colorize"] }
 
 [dev-dependencies]
 expect-test.workspace = true
diff --git a/crates/moonbuild/src/expect.rs b/crates/moonbuild/src/expect.rs
index 7e1276d8..064d3c78 100644
--- a/crates/moonbuild/src/expect.rs
+++ b/crates/moonbuild/src/expect.rs
@@ -48,6 +48,7 @@ pub struct BufferExpect {
     expect: String,
     actual: String,
     kind: TargetKind,
+    mode: Option<String>,
 }
 
 // something like array out of bounds, moonbit panic & abort catch by js
@@ -81,6 +82,7 @@ pub struct Target {
     kind: TargetKind,
     expect: String,
     actual: String,
+    mode: Option<String>,
 }
 
 #[derive(Debug, Default, serde::Serialize, serde::Deserialize)]
@@ -90,6 +92,7 @@ pub struct ExpectFailedRaw {
     pub expect: String,
     pub actual: String,
     pub snapshot: Option<bool>,
+    pub mode: Option<String>,
 }
 
 pub fn expect_failed_to_snapshot_result(efr: ExpectFailedRaw) -> SnapshotResult {
@@ -167,6 +170,8 @@ struct Replace {
 
     pub expect: String,
     pub expect_loc: Option<Location>,
+
+    pub mode: Option<String>,
 }
 
 impl Replace {
@@ -183,6 +188,7 @@ impl Replace {
                 kind: TargetKind::Trivial,
                 expect: self.expect.clone(),
                 actual: self.actual.clone(),
+                mode: self.mode.clone(),
             })
         } else {
             let is_pipe = self.actual_loc.ahead(&self.loc);
@@ -197,6 +203,7 @@ impl Replace {
                     kind: TargetKind::Pipe,
                     expect: self.expect.clone(),
                     actual: self.actual.clone(),
+                    mode: self.mode.clone(),
                 })
             } else {
                 // TODO: find comma
@@ -211,6 +218,7 @@ impl Replace {
                     kind: TargetKind::Call,
                     expect: self.expect.clone(),
                     actual: self.actual.clone(),
+                    mode: self.mode.clone(),
                 })
             }
         }
@@ -246,6 +254,7 @@ fn parse_expect_failed_message(msg: &str) -> anyhow::Result<Replace> {
         expect_loc,
         actual: j.actual,
         actual_loc,
+        mode: j.mode,
     })
 }
 
@@ -431,6 +440,7 @@ fn gen_patch(targets: HashMap<String, BTreeSet<Target>>) -> anyhow::Result<Packa
                 expect: t.expect,
                 actual: t.actual,
                 kind: t.kind,
+                mode: t.mode.clone(),
             });
         }
 
@@ -535,18 +545,28 @@ fn apply_patch(pp: &PackagePatch) -> anyhow::Result<()> {
                     }
                 }
 
-                if !patch.actual.contains('\n') && !patch.actual.contains('"') {
-                    output.push_str(&format!("{:?}", &patch.actual));
-                } else {
-                    let next_char = content_chars[usize::from(end)..].first();
-                    let prev_char = content_chars[..usize::from(start)].last();
-                    push_multi_line_string(
-                        &mut output,
-                        spaces + 2,
-                        &patch.actual,
-                        prev_char,
-                        next_char,
-                    );
+                match patch.mode.as_deref() {
+                    None => {
+                        if !patch.actual.contains('\n') && !patch.actual.contains('"') {
+                            output.push_str(&format!("{:?}", &patch.actual));
+                        } else {
+                            let next_char = content_chars[usize::from(end)..].first();
+                            let prev_char = content_chars[..usize::from(start)].last();
+                            push_multi_line_string(
+                                &mut output,
+                                spaces + 2,
+                                &patch.actual,
+                                prev_char,
+                                next_char,
+                            );
+                        }
+                    }
+                    Some("json") => {
+                        output.push_str(&patch.actual.to_string());
+                    }
+                    Some(mode) => {
+                        anyhow::bail!("unsupported mode: {:?} in expect testing", mode);
+                    }
                 }
 
                 if let Some(padding) = patch.right_padding {
@@ -639,6 +659,19 @@ pub fn render_expect_fail(msg: &str) -> anyhow::Result<()> {
     let json_str = &msg[EXPECT_FAILED.len()..];
     let rep = parse_expect_failed_message(json_str)?;
 
+    if let Some("json") = rep.mode.as_deref() {
+        let j_expect = serde_json_lenient::from_str(&rep.expect)?;
+        let j_actual = serde_json_lenient::from_str(&rep.actual)?;
+        let diffs = json_structural_diff::JsonDiff::diff(&j_expect, &j_actual, false);
+        if let Some(diff) = diffs.diff {
+            let diffs = json_structural_diff::colorize(&diff, true);
+            println!("inspect failed at {}", rep.loc.raw);
+            println!("{}", "Diff:".bold());
+            println!("{}", diffs);
+        }
+        return Ok(());
+    }
+
     let d = dissimilar::diff(&rep.expect, &rep.actual);
     println!(
         r#"expect test failed at {}