Quick answer
Single file: Chrome extension (5-10 sec). Bulk (1000 files): PowerShell + ImageMagick on Windows (1 min), Automator on Mac (2-3 min).
You have 100 HEIC photos to convert. Do you use the Chrome extension one-by-one, or batch convert with a script? Speed matters when you have hundreds or thousands.
heicconvert.site · HEIC to JPG Converter
Drop HEIC files here
or click to choose . up to 200 at once
HEIC
IMG_4827.HEIC
Done . 0.9s
HEIC
IMG_4828.HEIC
Done . 1.1s
HEIC
IMG_4829.HEIC
82%
3 of 28 converted
0 uploaded
Single file speed comparison
- Chrome extension: 5-10 sec (no upload delay).
- Cloudconvert (web): 15-30 sec (includes upload delay).
- iLoveIMG (web): 20-30 sec (upload delay + slower server).
- Preview (Mac): 20-30 sec (manual export required).
- Windows built-in: No built-in support (must use third-party tool).
Bulk (1000 files) speed comparison
- PowerShell + ImageMagick (Windows): 1 minute (fastest overall).
- Automator (Mac): 2-3 minutes (full batch automation).
- sips CLI (Mac): 3-5 minutes (slightly slower than Automator).
- XnConvert (desktop): 3-5 minutes (GUI-based bulk conversion).
- Chrome extension (manual one-by-one): 10-20 minutes (one file at a time).
Speed bottlenecks
- Web tools: Upload bandwidth is the bottleneck (5-10 sec per MB on typical internet).
- Local tools: Disk I/O is the bottleneck (3-5 MB/sec on typical SSD).
- CPU: Image conversion CPU time is minimal (modern CPUs very fast at JPEG encoding).
Practical speed for real workflows
- 10 photos: Chrome extension (50-100 sec) is fastest and simplest.
- 100 photos: Batch convert with Automator/PowerShell (5-10 sec total) is 5-10x faster.
- 1000+ photos: PowerShell script (1-2 minutes) is mandatory, manual conversion would take 2+ hours.
At-a-glance comparison
| Method | Single file | Bulk (1000) | Best use case |
|---|---|---|---|
| Chrome extension | 5-10 sec | 10-20 min | 1-10 files (simple) |
| Cloudconvert (web) | 15-30 sec | 3-5 min (parallel) | 5-50 files |
| PowerShell + ImageMagick | N/A | 1 min | 100+ files (Windows) |
| Automator (Mac) | N/A | 2-3 min | 100+ files (Mac) |
Frequently asked questions
Why is PowerShell so much faster than web tools?
No upload delay. Local disk I/O is 100-1000x faster than internet upload bandwidth.
Can I speed up web tool conversion?
No. Web tool speed is limited by upload bandwidth (typically 5-10 Mbps). PowerShell and Automator are always faster for bulk.
Is the Chrome extension slower than PowerShell?
Yes, for bulk. Extension converts one file at a time. PowerShell batch converts all files in parallel (one command processes whole folder). For single file, extension is slightly faster.
Why does Automator take 2-3 minutes for 1000 files?
Automator runs sequentially (one file at a time) and has overhead per-file. PowerShell + ImageMagick uses parallel processing (faster).
What is the optimal batch size for PowerShell?
PowerShell can handle 1000+ files in one command. Larger batches use more memory but process faster (less overhead).
