Rename 500 photos in a second with Python

Phones and cameras name files like IMG_20261001_4821.jpg. Renaming hundreds of them by hand takes most of an evening.

This script creates a folder of 500 camera-style files, then renames every one to a readable name with the trip name, the date and a running number. Change the trip name below and press Run. It really creates and renames the files, inside your browser's private file system.

Rename 500 photos in a second

IMG_20261001_4821.jpg → Goa_2026-10-01_001.jpg, for every file at once.

Trip name

→ press Run. The first run downloads Python (~4 MB, cached after that).

The Python behind it · 25 lines

1import os, time
2
3trip = "Goa"  # what to call the photos
4trip = trip.replace("/", "-").replace("\\", "-").strip() or "Trip"
5
6# Make a folder of 500 camera files, just like your phone dumps them
7folder = "/tmp/phone-photos"
8os.makedirs(folder, exist_ok=True)
9for f in os.listdir(folder):
10    os.remove(os.path.join(folder, f))
11for i in range(500):
12    open(f"{folder}/IMG_{20261001 + i // 50}_{4821 + i * 7}.jpg", "w").close()
13
14print("Before:", sorted(os.listdir(folder))[:3], "...")
15
16start = time.perf_counter()
17for n, name in enumerate(sorted(os.listdir(folder)), start=1):
18    day = name[4:12]  # the date is inside the camera's file name
19    new = f"{trip}_{day[:4]}-{day[4:6]}-{day[6:]}_{n:03}.jpg"
20    os.rename(f"{folder}/{name}", f"{folder}/{new}")
21took = (time.perf_counter() - start) * 1000
22
23print("After: ", sorted(os.listdir(folder))[:3], "...")
24print(f"\n✓ Renamed {len(os.listdir(folder))} photos in {took:.0f} ms")
25print("By hand at 5 seconds each, that's about 42 minutes.")

How the code works, step by step

1.Make the name safe
A / in a file name would point to a folder that does not exist, so it is swapped for a dash. The or "Trip" gives a fallback when the box is empty.
```
3trip = "Goa"  # what to call the photos
4trip = trip.replace("/", "-").replace("\\", "-").strip() or "Trip"
```

2.Create 500 test files

os.makedirs creates the folder, the first loop clears anything left from an earlier run, and the second creates 500 empty files with camera-style names: 50 per day over 10 days.

6# Make a folder of 500 camera files, just like your phone dumps them
7folder = "/tmp/phone-photos"
8os.makedirs(folder, exist_ok=True)
9for f in os.listdir(folder):
10    os.remove(os.path.join(folder, f))
11for i in range(500):
12    open(f"{folder}/IMG_{20261001 + i // 50}_{4821 + i * 7}.jpg", "w").close()

3.Rename every file

enumerate counts the files from 1. Slicing name[4:12] pulls the date out of the camera's name, the f-string builds the new name with a zero-padded number ({n:03} gives 001), and os.rename does the rename. time.perf_counter measures how long it took.

16start = time.perf_counter()
17for n, name in enumerate(sorted(os.listdir(folder)), start=1):
18    day = name[4:12]  # the date is inside the camera's file name
19    new = f"{trip}_{day[:4]}-{day[4:6]}-{day[6:]}_{n:03}.jpg"
20    os.rename(f"{folder}/{name}", f"{folder}/{new}")
21took = (time.perf_counter() - start) * 1000

4.Show before and after

Listing the folder again proves the rename happened. The last line compares that with doing it by hand at about 5 seconds a file.

23print("After: ", sorted(os.listdir(folder))[:3], "...")
24print(f"\n✓ Renamed {len(os.listdir(folder))} photos in {took:.0f} ms")
25print("By hand at 5 seconds each, that's about 42 minutes.")

Make it yours

On your own computer, point folder at a real folder of photos (try it on a copy first).
Read the real date a photo was taken from its EXIF data with the Pillow library.
Sort files into one folder per month instead of renaming them.

The lessons that teach this, in order

1. Strings 2. Modules & Imports 3. A mini automation pipeline

Build it yourself, step by step Start with Strings

Questions

Will this rename files on my computer?: Not here. In the browser, Python runs in a private, temporary file system, so it only touches the 500 test files it creates. To rename your own files, run the same code with Python installed on your computer.
What if two files end up with the same new name?: The running number at the end ({n:03}) makes every new name unique, so os.rename never overwrites a file.

Rename 500 photos in a second with Python

Phones and cameras name files like IMG_20261001_4821.jpg. Renaming hundreds of them by hand takes most of an evening.

1import os, time

3trip = "Goa" # what to call the photos

4trip = trip.replace("/", "-").replace("\\", "-").strip() or "Trip"

6# Make a folder of 500 camera files, just like your phone dumps them

7folder = "/tmp/phone-photos"

8os.makedirs(folder, exist_ok=True)

9for f in os.listdir(folder):

10 os.remove(os.path.join(folder, f))

11for i in range(500):

12 open(f"{folder}/IMG_{20261001 + i // 50}_{4821 + i * 7}.jpg", "w").close()

14print("Before:", sorted(os.listdir(folder))[:3], "...")

16start = time.perf_counter()

17for n, name in enumerate(sorted(os.listdir(folder)), start=1):

18 day = name[4:12] # the date is inside the camera's file name

19 new = f"{trip}_{day[:4]}-{day[4:6]}-{day[6:]}_{n:03}.jpg"

20 os.rename(f"{folder}/{name}", f"{folder}/{new}")

21took = (time.perf_counter() - start) * 1000

23print("After: ", sorted(os.listdir(folder))[:3], "...")

24print(f"\n✓ Renamed {len(os.listdir(folder))} photos in {took:.0f} ms")

25print("By hand at 5 seconds each, that's about 42 minutes.")

How the code works, step by step

1.Make the name safe

A / in a file name would point to a folder that does not exist, so it is swapped for a dash. The or "Trip" gives a fallback when the box is empty.

3trip = "Goa"  # what to call the photos
4trip = trip.replace("/", "-").replace("\\", "-").strip() or "Trip"

2.Create 500 test files

os.makedirs creates the folder, the first loop clears anything left from an earlier run, and the second creates 500 empty files with camera-style names: 50 per day over 10 days.

6# Make a folder of 500 camera files, just like your phone dumps them
7folder = "/tmp/phone-photos"
8os.makedirs(folder, exist_ok=True)
9for f in os.listdir(folder):
10    os.remove(os.path.join(folder, f))
11for i in range(500):
12    open(f"{folder}/IMG_{20261001 + i // 50}_{4821 + i * 7}.jpg", "w").close()

3.Rename every file

16start = time.perf_counter()
17for n, name in enumerate(sorted(os.listdir(folder)), start=1):
18    day = name[4:12]  # the date is inside the camera's file name
19    new = f"{trip}_{day[:4]}-{day[4:6]}-{day[6:]}_{n:03}.jpg"
20    os.rename(f"{folder}/{name}", f"{folder}/{new}")
21took = (time.perf_counter() - start) * 1000

4.Show before and after

Listing the folder again proves the rename happened. The last line compares that with doing it by hand at about 5 seconds a file.

23print("After: ", sorted(os.listdir(folder))[:3], "...")
24print(f"\n✓ Renamed {len(os.listdir(folder))} photos in {took:.0f} ms")
25print("By hand at 5 seconds each, that's about 42 minutes.")

Make it yours

On your own computer, point folder at a real folder of photos (try it on a copy first).

Read the real date a photo was taken from its EXIF data with the Pillow library.

Sort files into one folder per month instead of renaming them.

The lessons that teach this, in order

Questions

Will this rename files on my computer?

Not here. In the browser, Python runs in a private, temporary file system, so it only touches the 500 test files it creates. To rename your own files, run the same code with Python installed on your computer.

What if two files end up with the same new name?

The running number at the end ({n:03}) makes every new name unique, so os.rename never overwrites a file.