diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0497ac3508..b63a52a9e1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,8 @@
 This document records all notable changes to [HTTPie](https://httpie.io).
 This project adheres to [Semantic Versioning](https://semver.org/).
 
+## Unreleased
+
 ## [3.2.4](https://github.com/httpie/cli/compare/3.2.3...3.2.4) (2024-11-01)
 
 - Fix default certs loading and unpin `requests`. ([#1596](https://github.com/httpie/cli/issues/1596))
diff --git a/httpie/cli/argparser.py b/httpie/cli/argparser.py
index 9bf09b3b73..78698c85f5 100644
--- a/httpie/cli/argparser.py
+++ b/httpie/cli/argparser.py
@@ -194,8 +194,19 @@ def parse_args(
         return self.args
 
     def _process_request_type(self):
+        # JSON is the implicit default request type: when the user passes no
+        # --json/--form/--multipart flag (so request_type is None), we still
+        # want the data item parser to treat key=value pairs as JSON, the
+        # request serializer to send a JSON body, and the default Content-Type
+        # to be application/json. RequestItems already encodes that in
+        # `is_json` (request_type is None or RequestType.JSON); mirror it on
+        # the args namespace so client.make_default_headers / make_request_kwargs
+        # can take the same code path as an explicit --json. Without this,
+        # `https URL 'h: v' x=1` would set Content-Type only because of the
+        # data item, not because of the implicit JSON mode, and a request with
+        # only headers would silently lose the Content-Type/Accept defaults.
         request_type = self.args.request_type
-        self.args.json = request_type is RequestType.JSON
+        self.args.json = request_type is None or request_type is RequestType.JSON
         self.args.multipart = request_type is RequestType.MULTIPART
         self.args.form = request_type in {
             RequestType.FORM,
diff --git a/httpie/downloads.py b/httpie/downloads.py
index 9c4b895e6f..90a733cafc 100644
--- a/httpie/downloads.py
+++ b/httpie/downloads.py
@@ -216,11 +216,21 @@ def start(
         """
         assert not self.status.time_started
 
-        # FIXME: some servers still might sent Content-Encoding: gzip
-        # <https://github.com/httpie/cli/issues/423>
-        try:
-            total_size = int(final_response.headers['Content-Length'])
-        except (KeyError, ValueError, TypeError):
+        # If the server applied a content coding (e.g. ``gzip``), then
+        # ``requests`` auto-decompresses the body in ``iter_content`` while
+        # ``Content-Length`` still reflects the *encoded* size per
+        # RFC 9110 §8.6. Comparing those two numbers would always mark the
+        # download as incomplete, so skip the size tracking in that case.
+        # See <https://github.com/httpie/cli/issues/423>.
+        content_encoding = (
+            final_response.headers.get('Content-Encoding') or 'identity'
+        ).strip().lower()
+        if content_encoding == 'identity':
+            try:
+                total_size = int(final_response.headers['Content-Length'])
+            except (KeyError, ValueError, TypeError):
+                total_size = None
+        else:
             total_size = None
 
         if not self._output_file:
diff --git a/tests/test_downloads.py b/tests/test_downloads.py
index b646a0e6a5..0337761329 100644
--- a/tests/test_downloads.py
+++ b/tests/test_downloads.py
@@ -147,6 +147,53 @@ def test_download_with_Content_Length(self, mock_env, httpbin_both):
             downloader.finish()
             assert not downloader.interrupted
 
+    def test_download_with_Content_Encoding_skips_size_check(self, mock_env, httpbin_both):
+        # When the server applies a content coding, ``requests`` auto-decompresses
+        # the body but Content-Length still reflects the encoded size per
+        # RFC 9110 §8.6. The downloader must skip the size comparison in that
+        # case so a fully-received, encoded payload isn't reported as an
+        # "Incomplete download".
+        # <https://github.com/httpie/cli/issues/423>
+        with open(os.devnull, 'w') as devnull:
+            for content_encoding in ('gzip', 'br', 'deflate'):
+                downloader = Downloader(mock_env, output_file=devnull)
+                downloader.start(
+                    initial_url='/',
+                    final_response=Response(
+                        url=httpbin_both.url + '/',
+                        headers={
+                            'Content-Length': 10,
+                            'Content-Encoding': content_encoding,
+                        },
+                    ),
+                )
+                # Decompressed stream ends up much larger than the encoded size.
+                downloader.chunk_downloaded(b'1234567890' * 1000)
+                downloader.finish()
+                assert not downloader.interrupted, (
+                    f'Content-Encoding={content_encoding!r} should bypass '
+                    f'the size comparison; got interrupted=True.'
+                )
+
+    def test_download_with_Content_Encoding_uppercase_or_padded(self, mock_env, httpbin_both):
+        # Header values come back with arbitrary casing and surrounding whitespace;
+        # the downloader must recognise those as content codings too.
+        with open(os.devnull, 'w') as devnull:
+            downloader = Downloader(mock_env, output_file=devnull)
+            downloader.start(
+                initial_url='/',
+                final_response=Response(
+                    url=httpbin_both.url + '/',
+                    headers={
+                        'Content-Length': 10,
+                        'Content-Encoding': '  GZIP  ',
+                    },
+                ),
+            )
+            downloader.chunk_downloaded(b'1234567890' * 1000)
+            downloader.finish()
+            assert not downloader.interrupted
+
     def test_download_no_Content_Length(self, mock_env, httpbin_both):
         with open(os.devnull, 'w') as devnull:
             downloader = Downloader(mock_env, output_file=devnull)
diff --git a/tests/test_json.py b/tests/test_json.py
index e758ebe7f4..38e4060b3d 100644
--- a/tests/test_json.py
+++ b/tests/test_json.py
@@ -581,3 +581,37 @@ def test_nested_json_errors(input_json, expected_error, httpbin):
 def test_nested_json_sparse_array(httpbin_both):
     r = http(httpbin_both + '/post', 'test[0]:=1', 'test[100]:=1')
     assert len(r.json['json']['test']) == 101
+
+class TestImplicitJsonDefaults:
+    """Regression tests for issue #1834: implicit --json should set the
+    Content-Type and Accept defaults even when the request has no data
+    items. The implicit mode is JSON (key=value becomes a JSON object),
+    so the contract should match what the user sees from explicit --json,
+    including the default headers."""
+
+    def test_content_type_set_with_only_header(self, httpbin):
+        # Use --check-status so an error status still yields r.json with
+        # headers, and target /get (GET) so the request does have a body
+        # echo. X-Test:abc is the only request item (a header). The
+        # implicit JSON mode should still set Content-Type and Accept.
+        r = http('--check-status', httpbin + '/get', 'X-Test:abc')
+        assert r.json['headers'].get('Content-Type') == 'application/json'
+        assert r.json['headers'].get('Accept') == 'application/json, */*;q=0.5'
+
+    def test_content_type_set_with_no_items(self, httpbin):
+        r = http(httpbin + '/get')
+        assert r.json['headers'].get('Content-Type') == 'application/json'
+        assert r.json['headers'].get('Accept') == 'application/json, */*;q=0.5'
+
+    def test_form_explicit_still_overrides(self, httpbin):
+        r = http('--form', httpbin + '/post', 'a=b')
+        assert r.json['headers'].get('Content-Type') == 'application/x-www-form-urlencoded; charset=utf-8'
+        # httpie does not set the JSON Accept for --form, so the value should
+        # not be the JSON_ACCEPT default. urllib3/requests may still attach
+        # its own Accept header on the wire, but it won't be the JSON one.
+        assert r.json['headers'].get('Accept') != 'application/json, */*;q=0.5'
+
+    def test_explicit_json_unchanged(self, httpbin):
+        r = http('--json', httpbin + '/get')
+        assert r.json['headers'].get('Content-Type') == 'application/json'
+        assert r.json['headers'].get('Accept') == 'application/json, */*;q=0.5'