How to convert multiple images at once

Converting a few images one at a time is fine. Converting hundreds is tedious. True batch conversion processes multiple files in parallel, saving time on large jobs. OnlyFiles currently converts one image at a time, but because the conversion happens instantly in your browser (no server upload, no queue), serial conversion with OnlyFiles is fast enough for small to moderate batches. For very large batches, consider command-line tools or batch conversion alternatives.

Why batch conversion matters

If you're converting 10 images, one at a time is fine. If you're converting 100, it's tedious. If you're converting 1,000, it's impractical. Batch conversion processes multiple files at once, multiplying your speed. Many online batch tools claim to do this, but they require uploading all files to their servers first, which adds minutes of upload time. OnlyFiles works differently — each conversion is instant because it happens in your browser locally.

How OnlyFiles handles conversion speed

OnlyFiles runs conversions directly in your browser using JavaScript. This eliminates the slowest part of most online converters: uploading files to a server. With OnlyFiles, you drop an image, it converts in your browser in under a second, and you download it. No waiting for upload, no waiting for server processing, no waiting for download. This means converting images serially (one after another) with OnlyFiles is actually faster than waiting for a batch tool to upload 100 images to a server.

How to convert multiple images with OnlyFiles

For small batches (1–50 images): Open your converter, say /convert/jpg-to-png. Drop image 1, click convert, download. Drop image 2, click convert, download. Repeat. Because each conversion takes less than a second and you're not waiting for uploads, this is fast and straightforward.

For medium batches (50–500 images): Same approach, but open the converter in a new browser tab so you can keep it open. Drop, convert, download, repeat. Create a folder for your converted images and move them there as they download. This keeps your workspace organized.

For very large batches (1,000+ images): OnlyFiles is designed for quick, interactive conversion. For massive batch jobs, consider desktop tools like ImageMagick (free, command-line) or commercial batch converters that specialize in bulk processing.

Comparison: OnlyFiles vs. batch alternatives

Batch online converters: These tools allow you to upload 10, 50, or even 100 images at once. Sounds faster, but uploading 100 images to a server takes 2–5 minutes depending on file size and internet speed. Then the server processes them (usually serially anyway), and you download all results. Total time: 5–15 minutes. With OnlyFiles, converting 50 images serially takes about 1 minute (50 images × ~1 second per conversion) because there is no upload overhead.

Desktop software: Programs like Adobe Lightroom or IrfanView can batch convert on your computer. They're powerful and fast if you already have the software. OnlyFiles is a lighter alternative if you prefer not to install anything.

Command-line tools: ImageMagick and FFmpeg are free, run on your computer, and are incredibly fast for very large batches. If you're comfortable with the terminal, these are the best option for 1,000+ images. For most users, OnlyFiles or desktop software is simpler.

Tips for converting many images efficiently

• Keep the converter tab open — you don't need to navigate back and forth
• Organize your source images in a single folder for easy drag-and-drop
• Create a destination folder for converted images
• For 50+ images, keep a to-do list or use file explorer to track your progress
• If your browser becomes sluggish after many conversions, refresh the page to reset
• Use consistent file naming so you know which images you've already converted

Why OnlyFiles doesn't have batch conversion yet

Batch conversion is on the OnlyFiles roadmap. The reason it hasn't been added yet is that OnlyFiles prioritizes privacy and speed. Adding true parallel batch processing in the browser requires careful optimization to avoid overloading your computer. Because OnlyFiles handles images instantly with no server, the serial conversion approach is already very fast. A future batch feature will make this even more convenient, but for now, the fast serial approach works well for most users.

Getting started

Ready to convert multiple images? Pick an image converter from OnlyFiles:

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