diff --git a/Cargo.lock b/Cargo.lock
index 854db3f..1bfa1e1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,130 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "anstream"
+version = "0.6.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8acc5369981196006228e28809f761875c0327210a891e941f4c683b3a99529b"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "is_terminal_polyfill",
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle"
+version = "1.0.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "55cc3b69f167a1ef2e161439aa98aed94e6028e5f9a59be9a6ffb47aef1651f9"
+
+[[package]]
+name = "anstyle-parse"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3b2d16507662817a6a20a9ea92df6652ee4f94f914589377d69f3b21bc5798a9"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "79947af37f4177cfead1110013d678905c37501914fba0efea834c3fe9a8d60c"
+dependencies = [
+ "windows-sys",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "3.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca3534e77181a9cc07539ad51f2141fe32f6c3ffd4df76db8ad92346b003ae4e"
+dependencies = [
+ "anstyle",
+ "once_cell",
+ "windows-sys",
+]
+
+[[package]]
+name = "autocfg"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ace50bade8e6234aa140d9a2f552bbee1db4d353f69b8217bc503490fc1a9f26"
+
+[[package]]
+name = "bstr"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "234113d19d0d7d613b40e86fb654acf958910802bcceab913a4f9e7cda03b1a4"
+dependencies = [
+ "memchr",
+ "serde",
+]
+
+[[package]]
+name = "chrono"
+version = "0.4.40"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a7964611d71df112cb1730f2ee67324fcf4d0fc6606acbbe9bfe06df124637c"
+dependencies = [
+ "num-traits",
+]
+
+[[package]]
+name = "clap"
+version = "4.5.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8aa86934b44c19c50f87cc2790e19f54f7a67aedb64101c2e1a2e5ecfb73944"
+dependencies = [
+ "clap_builder",
+ "clap_derive",
+]
+
+[[package]]
+name = "clap_builder"
+version = "4.5.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2414dbb2dd0695280da6ea9261e327479e9d37b0630f6b53ba2a11c60c679fd9"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "clap_lex",
+ "strsim",
+]
+
+[[package]]
+name = "clap_derive"
+version = "4.5.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09176aae279615badda0765c0c0b3f6ed53f4709118af73cf4655d85d1530cd7"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "clap_lex"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f46ad14479a25103f283c0f10005961cf086d8dc42205bb44c46ac563475dca6"
+
 [[package]]
 name = "codespan-reporting"
 version = "0.12.0"
@@ -13,6 +137,12 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "colorchoice"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b63caa9aa9397e2d9480a9b13673856c78d8ac123288526c37d7839f2a86990"
+
 [[package]]
 name = "console"
 version = "0.15.11"
@@ -25,6 +155,31 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "crossbeam-deque"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9dd111b7b7f7d55b72c0a6ae361660ee5853c9af73f70c3c2ef6858b950e2e51"
+dependencies = [
+ "crossbeam-epoch",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-epoch"
+version = "0.9.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b82ac4a3c2ca9c3460964f020e1402edd5753411d7737aa39c3714ad1b5420e"
+dependencies = [
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
+
 [[package]]
 name = "diff"
 version = "0.1.13"
@@ -37,6 +192,72 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34aa73646ffb006b8f5147f3dc182bd4bcb190227ce861fc4a4844bf8e3cb2c0"
 
+[[package]]
+name = "escape8259"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5692dd7b5a1978a5aeb0ce83b7655c58ca8efdcb79d21036ea249da95afec2c6"
+
+[[package]]
+name = "globset"
+version = "0.4.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "54a1028dfc5f5df5da8a56a73e6c153c9a9708ec57232470703592a3f18e49f5"
+dependencies = [
+ "aho-corasick",
+ "bstr",
+ "log",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "heck"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
+
+[[package]]
+name = "hermit-abi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d231dfb89cfffdbc30e7fc41579ed6066ad03abda9e567ccafae602b97ec5024"
+
+[[package]]
+name = "ignore"
+version = "0.4.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d89fd380afde86567dfba715db065673989d6253f42b88179abd3eae47bda4b"
+dependencies = [
+ "crossbeam-deque",
+ "globset",
+ "log",
+ "memchr",
+ "regex-automata",
+ "same-file",
+ "walkdir",
+ "winapi-util",
+]
+
+[[package]]
+name = "include_dir"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "923d117408f1e49d914f1a379a309cffe4f18c05cf4e3d12e613a15fc81bd0dd"
+dependencies = [
+ "include_dir_macros",
+]
+
+[[package]]
+name = "include_dir_macros"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7cab85a7ed0bd5f0e76d93846e0147172bed2e2d3f859bcc33a8d9699cad1a75"
+dependencies = [
+ "proc-macro2",
+ "quote",
+]
+
 [[package]]
 name = "insta"
 version = "1.42.2"
@@ -59,20 +280,76 @@ dependencies = [
  "insta",
  "pretty_assertions",
  "toml-span",
+ "toml-test-harness",
 ]
 
+[[package]]
+name = "is_terminal_polyfill"
+version = "1.70.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"
+
+[[package]]
+name = "itoa"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a5f13b858c8d314ee3e8f639011f7ccefe71f97f96e50151fb991f267928e2c"
+
 [[package]]
 name = "libc"
 version = "0.2.171"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c19937216e9d3aa9956d9bb8dfc0b0c8beb6058fc4f7a4dc4d850edf86a237d6"
 
+[[package]]
+name = "libtest-mimic"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cc0bda45ed5b3a2904262c1bb91e526127aa70e7ef3758aba2ef93cf896b9b58"
+dependencies = [
+ "clap",
+ "escape8259",
+ "termcolor",
+ "threadpool",
+]
+
 [[package]]
 name = "linked-hash-map"
 version = "0.5.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0717cef1bc8b636c6e1c1bbdefc09e6322da8a9321966e8928ef80d20f7f770f"
 
+[[package]]
+name = "log"
+version = "0.4.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13dc2df351e3202783a1fe0d44375f7295ffb4049267b0f3018346dc122a1d94"
+
+[[package]]
+name = "memchr"
+version = "2.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
+
+[[package]]
+name = "num-traits"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "num_cpus"
+version = "1.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4161fcb6d602d4d2081af7c3a45852d875a03dd337a6bfdd6e06407b61342a43"
+dependencies = [
+ "hermit-abi",
+ "libc",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.21.3"
@@ -127,6 +404,38 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "regex-automata"
+version = "0.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "809e8dc61f6de73b46c85f4c96486310fe304c434cfa43669d7b40f711150908"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
+
+[[package]]
+name = "ryu"
+version = "1.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
+
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.219"
@@ -147,6 +456,18 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "serde_json"
+version = "1.0.140"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "20068b6e96dc6c9bd23e01df8827e6c7e1f2fddd43c21810382803c136b99373"
+dependencies = [
+ "itoa",
+ "memchr",
+ "ryu",
+ "serde",
+]
+
 [[package]]
 name = "similar"
 version = "2.7.0"
@@ -159,6 +480,12 @@ version = "1.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7fcf8323ef1faaee30a44a340193b1ac6814fd9b7b4e88e9d4519a3e4abe1cfd"
 
+[[package]]
+name = "strsim"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
+
 [[package]]
 name = "syn"
 version = "2.0.100"
@@ -179,6 +506,15 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "threadpool"
+version = "1.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d050e60b33d41c19108b32cea32164033a9013fe3b46cbd4457559bfbf77afaa"
+dependencies = [
+ "num_cpus",
+]
+
 [[package]]
 name = "toml-span"
 version = "0.5.0"
@@ -188,6 +524,39 @@ dependencies = [
  "smallvec",
 ]
 
+[[package]]
+name = "toml-test"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "704beaf8cc30d87aeb4f283f3ba3b091c7e786e5a0740e1eb6869a973634d58c"
+dependencies = [
+ "chrono",
+ "ryu",
+ "serde",
+ "serde_json",
+]
+
+[[package]]
+name = "toml-test-data"
+version = "1.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0cd230362857237e474ce9b5ba6576cf1858ecb14c04a6b376dc042538c9b93f"
+dependencies = [
+ "include_dir",
+]
+
+[[package]]
+name = "toml-test-harness"
+version = "0.4.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "81710e8e7f644081a22bdc205db4840e41f7fb673e3adbcacc001e25692b0f74"
+dependencies = [
+ "ignore",
+ "libtest-mimic",
+ "toml-test",
+ "toml-test-data",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.18"
@@ -200,6 +569,22 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1fc81956842c57dac11422a97c3b8195a1ff727f06e85c84ed2e8aa277c9a0fd"
 
+[[package]]
+name = "utf8parse"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
+
+[[package]]
+name = "walkdir"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29790946404f91d9c5d06f9874efddea1dc06c5efe94541a7d6863108e3a5e4b"
+dependencies = [
+ "same-file",
+ "winapi-util",
+]
+
 [[package]]
 name = "winapi-util"
 version = "0.1.9"
diff --git a/integ-tests/Cargo.toml b/integ-tests/Cargo.toml
index 70ce730..fdba561 100644
--- a/integ-tests/Cargo.toml
+++ b/integ-tests/Cargo.toml
@@ -10,3 +10,10 @@ codespan-reporting = "0.12"
 insta = { version = "1.34", features = ["json"] }
 pretty_assertions = "1.4"
 toml-span = { workspace = true, features = ["reporting", "serde"] }
+
+[dev-dependencies]
+toml-test-harness = "0.4"
+
+[[test]]
+name = "toml_test"
+harness = false
diff --git a/integ-tests/tests/toml_test.rs b/integ-tests/tests/toml_test.rs
new file mode 100644
index 0000000..4fcd6e1
--- /dev/null
+++ b/integ-tests/tests/toml_test.rs
@@ -0,0 +1,61 @@
+use std::str;
+
+use toml_test_harness as toml_test;
+
+fn main() {
+    let mut harness = toml_test::DecoderHarness::new(Decoder);
+    harness.version("1.0.0");
+    // ignore all test cases that contain datetimes
+    harness
+        .ignore([
+            "valid/datetime/",
+            "valid/example.toml",
+            "valid/spec-example-1.toml",
+            "valid/spec-example-1-compact.toml",
+            "valid/array/array.toml",
+            "valid/comment/everywhere.toml",
+            "valid/spec/table-7.toml",
+            "valid/spec/local-date-0.toml",
+            "valid/spec/local-date-time-0.toml",
+            "valid/spec/local-time-0.toml",
+            "valid/spec/offset-date-time-0.toml",
+            "valid/spec/offset-date-time-1.toml",
+        ])
+        .unwrap();
+    harness.test();
+}
+
+#[derive(Copy, Clone)]
+pub struct Decoder;
+impl toml_test_harness::Decoder for Decoder {
+    fn name(&self) -> &str {
+        "toml-span"
+    }
+    fn decode(&self, data: &[u8]) -> Result<toml_test::Decoded, toml_test::Error> {
+        let str = str::from_utf8(data).map_err(toml_test::Error::new)?;
+        let root_value = toml_span::parse(str).map_err(toml_test::Error::new)?;
+        Ok(transcode_value(root_value))
+    }
+}
+fn transcode_value(mut value: toml_span::Value<'_>) -> toml_test::Decoded {
+    use toml_span::value::ValueInner;
+    match value.take() {
+        ValueInner::String(val) => toml_test::Decoded::Value(val.to_string().into()),
+        ValueInner::Integer(val) => toml_test::Decoded::Value(val.into()),
+        ValueInner::Float(val) => toml_test::Decoded::Value(val.into()),
+        ValueInner::Boolean(val) => toml_test::Decoded::Value(val.into()),
+        ValueInner::Array(ary) => transcode_array(ary),
+        ValueInner::Table(tbl) => transcode_table(tbl),
+    }
+}
+fn transcode_array(array: toml_span::value::Array<'_>) -> toml_test::Decoded {
+    toml_test::Decoded::Array(array.into_iter().map(transcode_value).collect())
+}
+fn transcode_table(table: toml_span::value::Table<'_>) -> toml_test::Decoded {
+    toml_test::Decoded::Table(
+        table
+            .into_iter()
+            .map(|(key, val)| (key.name.to_string(), transcode_value(val)))
+            .collect(),
+    )
+}