diff --git a/common/file_helpers.py b/common/file_helpers.py
index 29ad219c07..a8ff410779 100644
--- a/common/file_helpers.py
+++ b/common/file_helpers.py
@@ -1,7 +1,10 @@
+import io
 import os
 import tempfile
 import contextlib
+import zstandard as zstd
 
+LOG_COMPRESSION_LEVEL = 10  # little benefit up to level 15. level ~17 is a small step change
 
 class CallbackReader:
   """Wraps a file, but overrides the read method to also
@@ -35,3 +38,16 @@ def atomic_write_in_dir(path: str, mode: str = 'w', buffering: int = -1, encodin
     yield tmp_file
     tmp_file_name = tmp_file.name
   os.replace(tmp_file_name, path)
+
+
+def get_upload_stream(filepath: str, compress: bool) -> io.BufferedReader | io.BytesIO:
+  if not compress:
+    return open(filepath, "rb")
+
+  # Compress the file on the fly and return a BytesIO stream
+  stream = io.BytesIO()
+  compressor = zstd.ZstdCompressor(level=LOG_COMPRESSION_LEVEL)
+  with open(filepath, "rb") as f:
+    compressor.copy_stream(f, stream)
+  stream.seek(0)
+  return stream
diff --git a/selfdrive/debug/qlog_size.py b/selfdrive/debug/qlog_size.py
index 11606c7589..6d494b6f75 100755
--- a/selfdrive/debug/qlog_size.py
+++ b/selfdrive/debug/qlog_size.py
@@ -6,7 +6,7 @@ from collections import defaultdict
 import matplotlib.pyplot as plt
 
 from cereal.services import SERVICE_LIST
-from openpilot.system.loggerd.uploader import LOG_COMPRESSION_LEVEL
+from openpilot.common.file_helpers import LOG_COMPRESSION_LEVEL
 from openpilot.tools.lib.logreader import LogReader
 from tqdm import tqdm
 
diff --git a/selfdrive/test/test_onroad.py b/selfdrive/test/test_onroad.py
index 1279a505dd..cba485c801 100644
--- a/selfdrive/test/test_onroad.py
+++ b/selfdrive/test/test_onroad.py
@@ -23,7 +23,7 @@ from openpilot.selfdrive.selfdrived.events import EVENTS, ET
 from openpilot.selfdrive.test.helpers import set_params_enabled, release_only
 from openpilot.system.hardware import HARDWARE
 from openpilot.system.hardware.hw import Paths
-from openpilot.system.loggerd.uploader import LOG_COMPRESSION_LEVEL
+from openpilot.common.file_helpers import LOG_COMPRESSION_LEVEL
 from openpilot.tools.lib.logreader import LogReader
 
 """
diff --git a/system/athena/athenad.py b/system/athena/athenad.py
index c926de9784..54e474f6e0 100755
--- a/system/athena/athenad.py
+++ b/system/athena/athenad.py
@@ -14,7 +14,6 @@ import sys
 import tempfile
 import threading
 import time
-import zstandard as zstd
 from dataclasses import asdict, dataclass, replace
 from datetime import datetime
 from functools import partial
@@ -31,11 +30,10 @@ import cereal.messaging as messaging
 from cereal import log
 from cereal.services import SERVICE_LIST
 from openpilot.common.api import Api
-from openpilot.common.file_helpers import CallbackReader
+from openpilot.common.file_helpers import CallbackReader, get_upload_stream
 from openpilot.common.params import Params
 from openpilot.common.realtime import set_core_affinity
 from openpilot.system.hardware import HARDWARE, PC
-from openpilot.system.loggerd.uploader import LOG_COMPRESSION_LEVEL
 from openpilot.system.loggerd.xattr_cache import getxattr, setxattr
 from openpilot.common.swaglog import cloudlog
 from openpilot.system.version import get_build_metadata
@@ -294,16 +292,13 @@ def _do_upload(upload_item: UploadItem, callback: Callable = None) -> requests.R
     path = strip_zst_extension(path)
     compress = True
 
-  with open(path, "rb") as f:
-    content = f.read()
-    if compress:
-      cloudlog.event("athena.upload_handler.compress", fn=path, fn_orig=upload_item.path)
-      content = zstd.compress(content, LOG_COMPRESSION_LEVEL)
-
-  with io.BytesIO(content) as data:
+  with get_upload_stream(path, compress) as stream:
+    stream.seek(0, os.SEEK_END)
+    content_length = stream.tell()
+    stream.seek(0)
     return requests.put(upload_item.url,
-                        data=CallbackReader(data, callback, len(content)) if callback else data,
-                        headers={**upload_item.headers, 'Content-Length': str(len(content))},
+                        data=CallbackReader(stream, callback, content_length) if callback else stream,
+                        headers={**upload_item.headers, 'Content-Length': str(content_length)},
                         timeout=30)
 
 
diff --git a/system/loggerd/uploader.py b/system/loggerd/uploader.py
index 0a21712096..4e1799c3df 100755
--- a/system/loggerd/uploader.py
+++ b/system/loggerd/uploader.py
@@ -1,5 +1,4 @@
 #!/usr/bin/env python3
-import io
 import json
 import os
 import random
@@ -8,12 +7,12 @@ import threading
 import time
 import traceback
 import datetime
-import zstandard as zstd
 from collections.abc import Iterator
 
 from cereal import log
 import cereal.messaging as messaging
 from openpilot.common.api import Api
+from openpilot.common.file_helpers import get_upload_stream
 from openpilot.common.params import Params
 from openpilot.common.realtime import set_core_affinity
 from openpilot.system.hardware.hw import Paths
@@ -29,7 +28,6 @@ MAX_UPLOAD_SIZES = {
                    # bugs, including ones that can cause massive log sizes
   "qcam": 5*1e6,
 }
-LOG_COMPRESSION_LEVEL = 10  # little benefit up to level 15. level ~17 is a small step change
 
 allow_sleep = bool(os.getenv("UPLOADER_SLEEP", "1"))
 force_wifi = os.getenv("FORCEWIFI") is not None
@@ -154,13 +152,9 @@ class Uploader:
     if fake_upload:
       return FakeResponse()
 
-    with open(fn, "rb") as f:
-      content = f.read()
-      if key.endswith('.zst') and not fn.endswith('.zst'):
-        content = zstd.compress(content, LOG_COMPRESSION_LEVEL)
-
-      with io.BytesIO(content) as data:
-        return requests.put(url, data=data, headers=headers, timeout=10)
+    compress = key.endswith('.zst') and not fn.endswith('.zst')
+    with get_upload_stream(fn, compress) as stream:
+      return requests.put(url, data=stream, headers=headers, timeout=10)
 
   def upload(self, name: str, key: str, fn: str, network_type: int, metered: bool) -> bool:
     try: