diff --git a/CHANGELOG.md b/CHANGELOG.md
index de36b19f2..d95b8253a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 
 - Enable structured logs by default; logs are now opt-out via `sentry_options_set_enable_logs(options, false)`. ([#1673](https://github.com/getsentry/sentry-native/pull/1673))
 - Crashpad: add macOS support for the `crashpad_wait_for_upload` flag. ([#1679](https://github.com/getsentry/sentry-native/pull/1679), [crashpad#152](https://github.com/getsentry/crashpad/pull/152))
+- Crashpad: add experimental support for large attachment uploads, opt-in via `sentry_options_set_enable_large_attachments`. ([#1674](https://github.com/getsentry/sentry-native/pull/1674), [crashpad#151](https://github.com/getsentry/crashpad/pull/151))
 
 **Fixes**:
 
diff --git a/examples/example.c b/examples/example.c
index 34f002c77..9c68643bb 100644
--- a/examples/example.c
+++ b/examples/example.c
@@ -565,6 +565,25 @@ main(int argc, char **argv)
         sentry_options_add_attachment(options, "./CMakeCache.txt");
     }
 
+    if (has_arg(argc, argv, "large-attachment")) {
+        sentry_options_set_enable_large_attachments(options, 1);
+        const char *large_file = ".sentry-large-attachment";
+        FILE *f = fopen(large_file, "wb");
+        if (f) {
+            char zeros[4096];
+            memset(zeros, 0, sizeof(zeros));
+            size_t remaining = 100 * 1024 * 1024;
+            while (remaining > 0) {
+                size_t chunk
+                    = remaining < sizeof(zeros) ? remaining : sizeof(zeros);
+                fwrite(zeros, 1, chunk, f);
+                remaining -= chunk;
+            }
+            fclose(f);
+            sentry_options_add_attachment(options, large_file);
+        }
+    }
+
     if (has_arg(argc, argv, "stdout")) {
         sentry_options_set_transport(
             options, sentry_transport_new(print_envelope));
diff --git a/external/crashpad b/external/crashpad
index 17b7aca16..18c866648 160000
--- a/external/crashpad
+++ b/external/crashpad
@@ -1 +1 @@
-Subproject commit 17b7aca1634f1a91018f1bba13f7941a2892e864
+Subproject commit 18c866648945ade8705a99bf5f372e4b1183e624
diff --git a/include/sentry.h b/include/sentry.h
index 3dde7bfea..28e1ac255 100644
--- a/include/sentry.h
+++ b/include/sentry.h
@@ -2351,6 +2351,21 @@ SENTRY_EXPERIMENTAL_API void sentry_options_set_http_retry(
 SENTRY_EXPERIMENTAL_API int sentry_options_get_http_retry(
     const sentry_options_t *opts);
 
+/**
+ * Enables or disables out-of-band upload of large attachments.
+ *
+ * When enabled, attachments above an internal size threshold are uploaded
+ * via a separate request before the envelope is sent, and referenced from
+ * the envelope by location instead of being embedded inline. When disabled,
+ * all attachments are embedded in the envelope regardless of size.
+ *
+ * Disabled by default.
+ */
+SENTRY_EXPERIMENTAL_API void sentry_options_set_enable_large_attachments(
+    sentry_options_t *opts, int enable_large_attachments);
+SENTRY_EXPERIMENTAL_API int sentry_options_get_enable_large_attachments(
+    const sentry_options_t *opts);
+
 /**
  * Enables or disables custom attributes parsing for structured logging.
  *
diff --git a/src/backends/sentry_backend_crashpad.cpp b/src/backends/sentry_backend_crashpad.cpp
index e63dd1fe6..83a4a8740 100644
--- a/src/backends/sentry_backend_crashpad.cpp
+++ b/src/backends/sentry_backend_crashpad.cpp
@@ -707,6 +707,9 @@ crashpad_backend_startup(
     }
 
     std::vector<std::string> arguments { "--no-rate-limit" };
+    if (options->enable_large_attachments) {
+        arguments.push_back("--enable-large-attachments");
+    }
 
     // Map sentry's log level to mini_chromium's LogSeverity. They diverge at
     // FATAL (sentry=3, mini_chromium=4); otherwise 1:1.
diff --git a/src/sentry_options.c b/src/sentry_options.c
index 995e407ce..100015cfe 100644
--- a/src/sentry_options.c
+++ b/src/sentry_options.c
@@ -96,6 +96,7 @@ sentry_options_new(void)
                                                             // both worlds
     opts->http_retry = false;
     opts->send_client_reports = true;
+    opts->enable_large_attachments = false;
 
     return opts;
 }
@@ -873,6 +874,19 @@ sentry_options_get_enable_metrics(const sentry_options_t *opts)
     return opts->enable_metrics;
 }
 
+void
+sentry_options_set_enable_large_attachments(
+    sentry_options_t *opts, int enable_large_attachments)
+{
+    opts->enable_large_attachments = !!enable_large_attachments;
+}
+
+int
+sentry_options_get_enable_large_attachments(const sentry_options_t *opts)
+{
+    return opts->enable_large_attachments;
+}
+
 void
 sentry_options_set_before_send_metric(sentry_options_t *opts,
     sentry_before_send_metric_function_t func, void *user_data)
diff --git a/src/sentry_options.h b/src/sentry_options.h
index 86ee949c2..0a063a3aa 100644
--- a/src/sentry_options.h
+++ b/src/sentry_options.h
@@ -82,6 +82,7 @@ struct sentry_options_s {
     void *before_send_metric_data;
     bool http_retry;
     bool send_client_reports;
+    bool enable_large_attachments;
 
     /* everything from here on down are options which are stored here but
        not exposed through the options API */
diff --git a/tests/__init__.py b/tests/__init__.py
index b98e38456..5b9603b3a 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -350,16 +350,21 @@ def deserialize_from(
         headers = json.loads(line)
         length = headers["length"]
         payload = f.read(length)
-        if headers.get("type") in [
-            "event",
-            "feedback",
-            "session",
-            "transaction",
-            "user_report",
-            "log",
-            "trace_metric",
-            "client_report",
-        ]:
+        if (
+            headers.get("type")
+            in [
+                "event",
+                "feedback",
+                "session",
+                "transaction",
+                "user_report",
+                "log",
+                "trace_metric",
+                "client_report",
+            ]
+            or headers.get("content_type")
+            == "application/vnd.sentry.attachment-ref+json"
+        ):
             rv = cls(headers=headers, payload=PayloadRef(json=json.loads(payload)))
         else:
             rv = cls(headers=headers, payload=payload)
diff --git a/tests/test_integration_tus.py b/tests/test_integration_tus.py
new file mode 100644
index 000000000..642eb7ef0
--- /dev/null
+++ b/tests/test_integration_tus.py
@@ -0,0 +1,97 @@
+import os
+
+import pytest
+
+from . import (
+    make_dsn,
+    run,
+    Envelope,
+    SENTRY_VERSION,
+)
+from .conditions import has_crashpad, has_http, is_qemu
+
+pytestmark = pytest.mark.skipif(not has_http, reason="tests need http")
+
+# fmt: off
+auth_header = (
+    f"Sentry sentry_key=uiaeosnrtdy, sentry_version=7, sentry_client=sentry.native/{SENTRY_VERSION}"
+)
+# fmt: on
+
+
+@pytest.mark.skipif(
+    not has_crashpad or is_qemu, reason="crashpad backend not available"
+)
+def test_tus_crash_crashpad(cmake, httpserver):
+    tmp_path = cmake(["sentry_example"], {"SENTRY_BACKEND": "crashpad"})
+
+    upload_uri = "/api/123456/upload/abc123def456789/"
+    upload_qs = "length=104857600&signature=xyz"
+    location = httpserver.url_for(upload_uri) + "?" + upload_qs
+
+    httpserver.expect_oneshot_request(
+        "/api/123456/upload/",
+        headers={"tus-resumable": "1.0.0"},
+    ).respond_with_data("OK", status=201, headers={"Location": location})
+
+    httpserver.expect_oneshot_request(
+        upload_uri,
+        method="PATCH",
+        headers={"tus-resumable": "1.0.0"},
+        query_string=upload_qs,
+    ).respond_with_data("", status=204)
+
+    httpserver.expect_oneshot_request(
+        "/api/123456/envelope/",
+        headers={"x-sentry-auth": auth_header},
+    ).respond_with_data("OK")
+
+    env = dict(os.environ, SENTRY_DSN=make_dsn(httpserver))
+
+    with httpserver.wait(timeout=15) as waiting:
+        run(
+            tmp_path,
+            "sentry_example",
+            ["log", "large-attachment", "crashpad-wait-for-upload", "crash"],
+            expect_failure=True,
+            env=env,
+        )
+    assert waiting.result
+
+    create_req = None
+    upload_req = None
+    envelope_req = None
+    for entry in httpserver.log:
+        req = entry[0]
+        if req.path == "/api/123456/upload/" and req.method == "POST":
+            create_req = req
+        elif upload_uri in req.path and req.method == "PATCH":
+            upload_req = req
+        elif "/envelope/" in req.path:
+            envelope_req = req
+
+    assert create_req is not None
+    assert upload_req is not None
+    assert envelope_req is not None
+    assert int(create_req.headers.get("upload-length")) == 100 * 1024 * 1024
+    assert upload_req.headers.get("content-type") == "application/offset+octet-stream"
+    assert upload_req.headers.get("upload-offset") == "0"
+
+    envelope = Envelope.deserialize(envelope_req.get_data())
+    attachment_ref = None
+    minidump_item = None
+    for item in envelope:
+        if item.headers.get("attachment_type") == "event.minidump":
+            minidump_item = item
+        if (
+            item.headers.get("content_type")
+            == "application/vnd.sentry.attachment-ref+json"
+            and item.headers.get("filename") == ".sentry-large-attachment"
+        ):
+            if hasattr(item.payload, "json") and "location" in item.payload.json:
+                attachment_ref = item
+
+    assert minidump_item is not None
+    assert attachment_ref is not None
+    assert attachment_ref.payload.json["location"] == location
+    assert attachment_ref.headers.get("attachment_length") == 100 * 1024 * 1024