diff --git a/ota.py b/ota.py
index 46fde72..6c8efa9 100644
--- a/ota.py
+++ b/ota.py
@@ -7,13 +7,17 @@ on the next boot rather than bricking the device.
 
 Strategy
 --------
-1. Fetch ota_manifest.txt from the repo to determine which files to sync.
-2. Compare SHA1 hashes with a local manifest (.ota_manifest.json).
-3. Download only changed or missing files, writing to .tmp first.
-4. On success, rename .tmp files into place and update the manifest.
-5. If anything fails mid-update, the manifest is not updated, so the
+1. Check if last boot was good (OK flag exists).
+2. If good, fetch remote commit SHA and compare with local — if unchanged,
+   skip file check entirely.
+3. If new commit or failed boot, fetch ota_manifest.txt from the repo
+   to determine which files to sync.
+4. Compare SHA1 hashes with a local manifest (.ota_manifest.json).
+5. Download only changed or missing files, writing to .tmp first.
+6. On success, rename .tmp files into place and update the manifest.
+7. If anything fails mid-update, the manifest is not updated, so the
    next boot will retry. Partially written .tmp files are cleaned up.
-6. A "safety" flag file (.ota_ok) is written by main.py on successful
+8. A "safety" flag file (.ota_ok) is written by main.py on successful
    startup. If it is absent on boot, the previous update is suspected
    bad — the manifest is wiped so all files are re-fetched cleanly.
 
@@ -146,6 +150,26 @@ def _match_pattern(name, pattern):
         i += 1
     return i == n and j == m
 
+def _fetch_commit_sha():
+    url = (
+        f"{GITEA_BASE}/api/v1/repos/{REPO_OWNER}/{REPO_NAME}"
+        f"/branches/{REPO_BRANCH}"
+    )
+    info(f"Fetching commit from {url}")
+    try:
+        r = urequests.get(url, headers=_headers())
+        info(f"Response status: {r.status_code}")
+        if r.status_code == 200:
+            data = r.json()
+            r.close()
+            sha = data.get("commit", {}).get("sha")
+            info(f"Got commit: {sha}")
+            return sha
+        r.close()
+    except Exception as e:
+        log_err(f"Failed to fetch commit: {e}")
+    return None
+
 def _fetch_manifest():
     url = (
         f"{GITEA_BASE}/api/v1/repos/{REPO_OWNER}/{REPO_NAME}"
@@ -223,9 +247,11 @@ def _load_manifest():
     except Exception:
         return {}
 
-def _save_manifest(manifest):
+def _save_manifest(manifest, commit_sha=None):
     try:
         with open(MANIFEST_FILE, "w") as f:
+            if commit_sha:
+                manifest["_commit"] = commit_sha
             ujson.dump(manifest, f)
     except Exception as e:
         warn(f"Could not save manifest: {e}")
@@ -311,7 +337,7 @@ def _fetch_file_list():
     fetch_matching(root, manifest_patterns)
     return files
 
-def _do_update():
+def _do_update(commit_sha=None):
     """
     Fetch file list, download changed files, update manifest.
     Returns True if all succeeded (or nothing needed updating).
@@ -348,11 +374,10 @@ def _do_update():
 
     if failed:
         log_err(f"Update incomplete — {len(failed)} file(s) failed: {failed}")
-        # Save partial manifest so successful files aren't re-downloaded
-        _save_manifest(manifest)
+        _save_manifest(manifest, commit_sha)
         return False
 
-    _save_manifest(manifest)
+    _save_manifest(manifest, commit_sha)
 
     if updated:
         info(f"Update complete — {len(updated)} file(s) updated: {updated}")
@@ -371,6 +396,8 @@ def update():
 
     - If the OK flag is missing, the previous boot is assumed to have
       failed — wipes the manifest so everything is re-fetched cleanly.
+    - If the commit hash hasn't changed and last boot was good, skip
+      file comparison entirely.
     - Runs the update.
     - Clears the OK flag so main.py must re-assert it on successful start.
     """
@@ -380,17 +407,33 @@ def update():
 
     load_config()
 
-    if not _ok_flag_exists():
+    ok_flag = _ok_flag_exists()
+    manifest = _load_manifest()
+
+    if not ok_flag:
         warn("OK flag missing — last boot may have failed")
         warn("Wiping manifest to force full re-fetch")
         _wipe_manifest()
+        manifest = {}
     else:
         info("OK flag present — last boot was good")
 
+    commit_sha = _fetch_commit_sha()
+
+    if ok_flag and commit_sha and manifest.get("_commit") == commit_sha:
+        info(f"Commit unchanged ({commit_sha[:8]}) — skipping file check")
+        info("-" * 40)
+        return
+
+    if commit_sha:
+        info(f"Remote commit: {commit_sha[:8]}")
+    else:
+        warn("Could not fetch remote commit — proceeding with file check")
+
     # Clear the flag now; main.py must call ota.mark_ok() to re-set it
     _clear_ok_flag()
 
-    success = _do_update()
+    success = _do_update(commit_sha)
 
     if success:
         info("OTA check complete — booting application")