diff --git a/scrapers/capture_passive_playwright_async.py b/scrapers/capture_passive_playwright_async.py
index f4fd76e..32f7db4 100644
--- a/scrapers/capture_passive_playwright_async.py
+++ b/scrapers/capture_passive_playwright_async.py
@@ -249,23 +249,28 @@ async def run(args):
                         try:
                             parsed = json.loads(txt)
                             pretty = json.dumps(parsed, ensure_ascii=False, indent=2)
-                            fname = f"{safe}_{h}_{ts}.json"
-                            body_path = str(output / fname)
-                            save_text(output / fname, pretty)
-                            try:
-                                print(f"{now_ts()}\tSAVED\t{body_path}")
-                            except Exception:
-                                pass
+                            content_bytes = pretty.encode('utf-8')
                             excerpt = pretty[:800]
+                            use_text = pretty
+                            ext = 'json'
                         except Exception:
-                            fname = f"{safe}_{h}_{ts}.txt"
-                            body_path = str(output / fname)
-                            save_text(output / fname, txt)
+                            content_bytes = txt.encode('utf-8')
+                            excerpt = txt[:800]
+                            use_text = txt
+                            ext = 'txt'
+
+                        # deterministic filename based on content hash (sha1)
+                        content_sha1 = hashlib.sha1(content_bytes).hexdigest()
+                        fname = f"{safe}_{content_sha1}.{ext}"
+                        body_path = str(output / fname)
+
+                        # if file already exists, don't rewrite body; just update meta/index
+                        if not os.path.exists(body_path):
+                            save_text(output / fname, use_text)
                             try:
                                 print(f"{now_ts()}\tSAVED\t{body_path}")
                             except Exception:
                                 pass
-                            excerpt = txt[:800]
                     else:
                         try:
                             data = await resp.body()
@@ -278,26 +283,29 @@ async def run(args):
                         ext = guess_ext(ctype)
                         # Put images into an images/ subdirectory, other binaries into assets/
                         if ctype.startswith('image/'):
-                            # Images don't need per-capture timestamps; use stable names with hash
                             subdir = output / 'images'
                             subdir.mkdir(parents=True, exist_ok=True)
-                            fname = f"{safe}_{h}.{ext}"
+                            content_sha1 = hashlib.sha1(data).hexdigest()
+                            fname = f"{safe}_{content_sha1}.{ext}"
                             body_path = str(subdir / fname)
-                            save_binary(subdir / fname, data)
-                            try:
-                                print(f"{now_ts()}\tSAVED\t{body_path}")
-                            except Exception:
-                                pass
+                            if not os.path.exists(body_path):
+                                save_binary(subdir / fname, data)
+                                try:
+                                    print(f"{now_ts()}\tSAVED\t{body_path}")
+                                except Exception:
+                                    pass
                         else:
                             subdir = output / 'assets'
                             subdir.mkdir(parents=True, exist_ok=True)
-                            fname = f"{safe}_{h}_{ts}.{ext}"
+                            content_sha1 = hashlib.sha1(data).hexdigest()
+                            fname = f"{safe}_{content_sha1}.{ext}"
                             body_path = str(subdir / fname)
-                            save_binary(subdir / fname, data)
-                            try:
-                                print(f"{now_ts()}\tSAVED\t{body_path}")
-                            except Exception:
-                                pass
+                            if not os.path.exists(body_path):
+                                save_binary(subdir / fname, data)
+                                try:
+                                    print(f"{now_ts()}\tSAVED\t{body_path}")
+                                except Exception:
+                                    pass
                 except Exception:
                     # final fallback: try binary
                     try:
@@ -340,11 +348,12 @@ async def run(args):
                 except Exception:
                     content_hash = None
 
-                # prepare the meta filename we'll write for this response
-                new_meta_name = f"{safe}_{h}_{ts}.meta.json"
+                # prepare the meta filename we'll write for this response (canonical by content when available)
+                meta_base = content_hash or h
+                new_meta_name = f"{safe}_{meta_base}.meta.json"
                 new_meta_abs = os.path.abspath(str(output / new_meta_name))
 
-                # If older responses exist with the same content, delete them (fast in-memory lookup)
+                # If older responses exist with the same content, handle them according to dedupe policy
                 try:
                     matches = in_memory_index.get(content_hash, []) if content_hash else []
                     for j in matches:
@@ -352,20 +361,55 @@ async def run(args):
                         metaf = j.get('meta_file')
                         try:
                             if body and os.path.exists(body) and os.path.abspath(body) != os.path.abspath(body_path):
-                                os.remove(body)
+                                if args.dry_run:
+                                    print(f"DRYRUN: would remove old body {body}")
+                                else:
+                                    if args.dedupe_policy == 'delete':
+                                        os.remove(body)
+                                    elif args.dedupe_policy == 'move':
+                                        dupdir = output / 'duplicates'
+                                        dupdir.mkdir(parents=True, exist_ok=True)
+                                        try:
+                                            os.replace(body, dupdir / os.path.basename(body))
+                                        except Exception:
+                                            os.remove(body)
+                                    elif args.dedupe_policy == 'symlink':
+                                        # replace old body with symlink to canonical
+                                        try:
+                                            os.remove(body)
+                                            os.symlink(os.path.abspath(body_path), body)
+                                        except Exception:
+                                            pass
                                 try:
                                     with open(output / '_debug_events.log', 'a', encoding='utf-8') as dbg:
-                                        dbg.write(f"{now_ts()}\tDELETED_OLD_BODY\t{body}\n")
+                                        dbg.write(f"{now_ts()}\tDEDUP_BODY\t{body}\n")
                                 except Exception:
                                     pass
                         except Exception:
                             pass
                         try:
                             if metaf and os.path.exists(metaf) and os.path.abspath(metaf) != new_meta_abs:
-                                os.remove(metaf)
+                                if args.dry_run:
+                                    print(f"DRYRUN: would remove old meta {metaf}")
+                                else:
+                                    if args.dedupe_policy == 'delete':
+                                        os.remove(metaf)
+                                    elif args.dedupe_policy == 'move':
+                                        dupdir = output / 'duplicates'
+                                        dupdir.mkdir(parents=True, exist_ok=True)
+                                        try:
+                                            os.replace(metaf, dupdir / os.path.basename(metaf))
+                                        except Exception:
+                                            os.remove(metaf)
+                                    elif args.dedupe_policy == 'symlink':
+                                        try:
+                                            os.remove(metaf)
+                                            os.symlink(new_meta_abs, metaf)
+                                        except Exception:
+                                            pass
                                 try:
                                     with open(output / '_debug_events.log', 'a', encoding='utf-8') as dbg:
-                                        dbg.write(f"{now_ts()}\tDELETED_OLD_META\t{metaf}\n")
+                                        dbg.write(f"{now_ts()}\tDEDUP_META\t{metaf}\n")
                                 except Exception:
                                     pass
                         except Exception:
@@ -383,10 +427,10 @@ async def run(args):
                     'response_excerpt': excerpt,
                     'content_hash': content_hash,
                 }
-                meta_name = f"{safe}_{h}_{ts}.meta.json"
-                save_text(output / meta_name, json.dumps(meta, ensure_ascii=False, indent=2))
+                # write canonical meta (update if exists)
+                save_text(output / new_meta_name, json.dumps(meta, ensure_ascii=False, indent=2))
                 try:
-                    entry = {'url': url, 'resource_type': rtype, 'timestamp': ts, 'body_file': body_path, 'meta_file': str(output / meta_name), 'excerpt': excerpt, 'content_hash': content_hash}
+                    entry = {'url': url, 'resource_type': rtype, 'timestamp': ts, 'body_file': body_path, 'meta_file': str(output / new_meta_name), 'excerpt': excerpt, 'content_hash': content_hash}
                     with open(index_path, 'a', encoding='utf-8') as idx:
                         idx.write(json.dumps(entry, ensure_ascii=False) + '\n')
                     # update in-memory index
@@ -485,6 +529,8 @@ def parse_args():
     parser.add_argument('--post-login-selector', default='#ds-app', help='Selector that indicates a successful login')
     parser.add_argument('--channel', default=os.getenv('PLAYWRIGHT_CHROME_CHANNEL', 'chrome'))
     parser.add_argument('--capture-types', default='xhr,fetch,document,other')
+    parser.add_argument('--dedupe-policy', default='delete', choices=['delete', 'move', 'keep', 'symlink'], help="What to do with older duplicate files: delete/move/keep/symlink")
+    parser.add_argument('--dry-run', action='store_true', help='If set, show dedupe actions without performing them')
     return parser.parse_args()
 
 
diff --git a/scrapers/migrate_captured_files.py b/scrapers/migrate_captured_files.py
new file mode 100644
index 0000000..01a9bc2
--- /dev/null
+++ b/scrapers/migrate_captured_files.py
@@ -0,0 +1,213 @@
+#!/usr/bin/env python3
+"""Migrate timestamped captured files to content-hash deterministic names.
+
+This script scans an output capture directory (default: xhr_captured_async),
+finds body files and their meta files that include timestamps in filenames,
+computes content SHA1, renames/moves them to canonical names like
+`{safe}_{sha1}.json` or `{safe}_{sha1}.{ext}` under the same directory structure,
+updates meta content (response_body_file) and meta filename to `{safe}_{sha1}.meta.json`,
+and rewrites `capture_index.jsonl` so entries point to the canonical files.
+
+It supports --dry-run and --dedupe-policy (delete/move/keep/symlink) for handling
+old duplicates that would collide on the canonical name.
+
+Usage:
+  python scrapers/migrate_captured_files.py --input-dir xhr_captured_async --dry-run
+
+"""
+from __future__ import annotations
+
+import argparse
+import hashlib
+import json
+import os
+import shutil
+from pathlib import Path
+from typing import Dict, List
+
+
+def compute_sha1(path: Path) -> str:
+    h = hashlib.sha1()
+    with open(path, "rb") as f:
+        while True:
+            b = f.read(8192)
+            if not b:
+                break
+            h.update(b)
+    return h.hexdigest()
+
+
+def canonical_name_for(path: Path, safe: str, sha1: str) -> Path:
+    # preserve extension
+    ext = path.suffix.lstrip('.')
+    if not ext:
+        ext = 'bin'
+    return path.with_name(f"{safe}_{sha1}.{ext}")
+
+
+def canonical_meta_name(safe: str, sha1: str, directory: Path) -> Path:
+    return directory / f"{safe}_{sha1}.meta.json"
+
+
+def find_safe_from_filename(fname: str) -> str:
+    # safe prefix is everything before the first '_<sha_or_timestamp>' pattern
+    # but we can be conservative: find the substring up to the first '_[0-9a-f]{8,}' or a timestamp pattern
+    import re
+    m = re.match(r"^(.+?)_(?:[0-9a-f]{8,32}|\d{8}T\d{6}Z|\d{4}-\d{2}-\d{2}T)", fname)
+    if m:
+        return m.group(1)
+    # fallback: strip final numeric groups
+    parts = fname.split('_')
+    if len(parts) > 1:
+        return '_'.join(parts[:-1])
+    return fname
+
+
+def load_index(index_path: Path) -> List[Dict]:
+    if not index_path.exists():
+        return []
+    out = []
+    with open(index_path, 'r', encoding='utf-8') as f:
+        for line in f:
+            line = line.strip()
+            if not line:
+                continue
+            try:
+                out.append(json.loads(line))
+            except Exception:
+                continue
+    return out
+
+
+def write_index(index_path: Path, entries: List[Dict]):
+    with open(index_path, 'w', encoding='utf-8') as f:
+        for e in entries:
+            f.write(json.dumps(e, ensure_ascii=False) + '\n')
+
+
+def migrate(input_dir: Path, dedupe_policy: str = 'delete', dry_run: bool = True):
+    # gather candidate files: top-level json/text files and files in images/ and assets/
+    files = list(input_dir.glob('*.json')) + list(input_dir.glob('*.txt')) + list(input_dir.glob('*.bin'))
+    files += list(input_dir.joinpath('images').glob('*')) if (input_dir / 'images').exists() else []
+    files += list(input_dir.joinpath('assets').glob('*')) if (input_dir / 'assets').exists() else []
+
+    # map sha1 -> canonical path (to detect collisions)
+    canonical_map: Dict[str, Path] = {}
+    # entries to update in index: old_path -> new_path
+    path_updates: Dict[str, str] = {}
+
+    for f in files:
+        if f.is_dir():
+            continue
+        # skip meta files
+        if f.name.endswith('.meta.json'):
+            continue
+        try:
+            sha1 = compute_sha1(f)
+        except Exception as e:
+            print(f"Failed to hash {f}: {e}")
+            continue
+        safe = find_safe_from_filename(f.name)
+        # canonical target
+        target = f.with_name(f"{safe}_{sha1}{f.suffix}")
+        # if already canonical, skip
+        if f.resolve() == target.resolve():
+            canonical_map[sha1] = target
+            continue
+        # if canonical target exists and is different file -> dedupe action
+        if target.exists() and target.resolve() != f.resolve():
+            print(f"Collision: {f} -> {target} (already exists)")
+            if dry_run:
+                print(f"DRYRUN would {dedupe_policy} {f}")
+            else:
+                if dedupe_policy == 'delete':
+                    f.unlink()
+                elif dedupe_policy == 'move':
+                    dupdir = input_dir / 'duplicates'
+                    dupdir.mkdir(parents=True, exist_ok=True)
+                    shutil.move(str(f), str(dupdir / f.name))
+                elif dedupe_policy == 'symlink':
+                    try:
+                        f.unlink()
+                    except Exception:
+                        pass
+                    try:
+                        os.symlink(str(target.resolve()), str(f))
+                    except Exception:
+                        pass
+                elif dedupe_policy == 'keep':
+                    pass
+            path_updates[str(f)] = str(target)
+            canonical_map[sha1] = target
+            continue
+        # otherwise move/rename to canonical target
+        print(f"Renaming: {f} -> {target}")
+        if not dry_run:
+            try:
+                os.replace(str(f), str(target))
+            except Exception as e:
+                print(f"Failed to move {f} -> {target}: {e}")
+                continue
+        path_updates[str(f)] = str(target)
+        canonical_map[sha1] = target
+
+    # Update meta files: for any meta files that point to old body paths, rewrite them
+    metas = list(input_dir.glob('*.meta.json')) + list(input_dir.joinpath('images').glob('*.meta.json')) if (input_dir / 'images').exists() else []
+    metas += list(input_dir.joinpath('assets').glob('*.meta.json')) if (input_dir / 'assets').exists() else []
+    for m in metas:
+        try:
+            with open(m, 'r', encoding='utf-8') as f:
+                jd = json.load(f)
+        except Exception:
+            continue
+        bf = jd.get('response_body_file')
+        if bf and bf in path_updates:
+            newbf = path_updates[bf]
+            jd['response_body_file'] = newbf
+            # write canonical meta name
+            safe = find_safe_from_filename(os.path.basename(newbf))
+            sha1 = compute_sha1(Path(newbf)) if Path(newbf).exists() else None
+            if sha1:
+                new_meta = m.with_name(f"{safe}_{sha1}.meta.json")
+            else:
+                new_meta = m
+            print(f"Updating meta {m} -> {new_meta}")
+            if not dry_run:
+                with open(new_meta, 'w', encoding='utf-8') as out:
+                    json.dump(jd, out, ensure_ascii=False, indent=2)
+                if new_meta.resolve() != m.resolve():
+                    try:
+                        m.unlink()
+                    except Exception:
+                        pass
+            path_updates[str(m)] = str(new_meta)
+
+    # Rewrite capture_index.jsonl
+    idx_path = input_dir / 'capture_index.jsonl'
+    index_entries = load_index(idx_path)
+    changed = False
+    for e in index_entries:
+        bf = e.get('body_file')
+        mf = e.get('meta_file')
+        if bf and bf in path_updates:
+            e['body_file'] = path_updates[bf]
+            changed = True
+        if mf and mf in path_updates:
+            e['meta_file'] = path_updates[mf]
+            changed = True
+    if changed:
+        print(f"Updating index {idx_path}")
+        if not dry_run:
+            write_index(idx_path, index_entries)
+
+    print('Migration complete')
+
+
+if __name__ == '__main__':
+    p = argparse.ArgumentParser()
+    p.add_argument('--input-dir', default='xhr_captured_async')
+    p.add_argument('--dedupe-policy', default='delete', choices=['delete', 'move', 'keep', 'symlink'])
+    p.add_argument('--dry-run', action='store_true')
+    args = p.parse_args()
+
+    migrate(Path(args.input_dir), dedupe_policy=args.dedupe_policy, dry_run=args.dry_run)