The simplest way to change a photo file type
The fastest way to change a photo file type is to open it in the program already on your computer and save it as a different format. On Windows, that's usually Photos or Paint. On Mac, it's Preview. You do not need to read anything or use a website.
Open the photo, go to File > Save As (or Export As), choose your new format from the dropdown menu, and click Save. The original photo stays unchanged. You now have two files: the old one in its original format and the new one in the format you chose.
The most common photo formats are JPEG (smaller files, good for sharing), PNG (keeps transparent backgrounds, larger files), and WebP (newer, smaller than JPEG, not supported everywhere yet). Which one you need depends on where you're sending the photo or what you're using it for.
Key Takeaways
- Windows Photos, Mac Preview, and Paint can all change photo formats without downloading anything new.
- JPEG is the standard for photos you're sharing or emailing because the file size is small.
- PNG is better if you need a transparent background or if the image has text or sharp lines.
- The Save As or Export As menu is where you choose the new format before saving.
- Your original photo is not changed — you get a new file in the format you picked.
How to change file type in Windows Photos
Open the photo in the Photos app (it comes with Windows). Click the three dots in the top right corner, then select "Edit" or "Open with" depending on your Windows version. Once the photo is open, look for the menu button (three horizontal lines or three dots) and select "Save as" or "Export."
A window will open asking where you want to save the file. At the bottom, you'll see a dropdown that says "JPEG" or another format. Click it and choose PNG, WebP, BMP, or GIF. Type a new name for the file (or keep the same name — Windows will add the new extension automatically). Click Save.
If Photos doesn't open your file, right-click the photo, select "Open with," and choose Paint instead. Paint has a simpler interface: File > Save As, then pick your format from the "Save as type" dropdown at the bottom of the window.
How to change file type on Mac using Preview
Open the photo in Preview (it opens automatically when you double-click most image files on Mac). Go to File > Export. A dialog box appears with your format options.
Click the "Format" dropdown and choose JPEG, PNG, TIFF, or GIF. You can also adjust the quality slider if you're saving as JPEG — moving it left makes the file smaller but slightly blurrier, moving it right keeps more detail but makes the file larger. Type a new filename and click Save.
If you want to change the format of multiple photos at once, Preview can do that too. Open the first photo, then go to File > Open and select all the photos you want to convert (hold Command and click each one). Export them all at once by going to File > Export and choosing your format.
Understanding the most common photo formats
JPEG is the standard for photographs. It compresses the image to make the file smaller, which is why it's used for email, social media, and websites. When you compress a JPEG, you lose some detail, but the loss is usually invisible to the human eye unless you compress it heavily. JPEG files cannot have transparent backgrounds.
PNG keeps all the original detail and supports transparent backgrounds, which is why designers use it for logos and graphics. PNG files are larger than JPEG files because they don't compress as much. Use PNG when the image has text, sharp lines, or when you need the background to be see-through.
WebP is newer and smaller than JPEG while keeping similar quality. It's supported by most modern browsers and phones, but some older devices and programs don't recognize it yet. If you're uploading to a website that accepts it, WebP is a good choice because it saves storage space.
GIF is used for straightforward images and animations. It supports transparent backgrounds and can show movement, but it only supports 256 colors, so it's not suitable for photographs. Use GIF only if you need animation or if you're working with very straightforward graphics.
When to use each format
| Format | Best for | File size | Transparent background |
|---|---|---|---|
| JPEG | Photos, email, social media | Small | No |
| PNG | Graphics, logos, images with text | Large | Yes |
| WebP | Websites, storage-conscious sharing | Very small | Yes |
| GIF | straightforward graphics, animations | Small | Yes |
What happens to image quality when you change formats
When you convert from one format to another, the quality depends on which direction you're going. Converting from JPEG to PNG does not improve the photo — PNG will just store the same compressed version in a larger file. The detail that JPEG threw away is gone.
Converting from PNG to JPEG makes the file smaller but introduces compression artifacts, which look like small blocks or blurriness around sharp edges. This is usually fine for photos but noticeable in graphics with text or clean lines.
Converting between PNG and WebP, or between PNG and GIF, preserves the image data but changes how it's stored. The visual quality stays the same, though GIF will reduce the number of colors if the original image has more than 256.
Using online converters if your computer doesn't have the right program
If you're on a computer without the programs mentioned above, or if you need to convert many files at once, online converters like CloudConvert, Zamzar, or Convertio can do the job. Upload your photo, choose your new format, and read the result.
Online converters are convenient, but they do send your photo to someone else's server. If the photo contains personal information or you're concerned about privacy, use the built-in programs on your computer instead — they work offline and keep your files on your device.
Most online converters are free for small files. Some limit how many conversions you can do per day or charge for bulk conversion. Read the terms before uploading sensitive images.
Frequently Asked Questions
Will changing the file type make my photo look different?
It depends on which formats you're converting between. JPEG to PNG won't improve quality because the compression is already done. PNG to JPEG will make the file smaller but may introduce slight blurriness. PNG to WebP or GIF keeps the same visual quality but stores it differently.
Can I change a photo back to its original format?
Yes, you can convert it back the same way you converted it the first time. However, if you converted from JPEG to PNG and then back to JPEG, the second JPEG will not look as good as the original because JPEG compresses twice. Always keep the original file if you think you might need it later.
What format should I use if I'm uploading to social media?
Most social media platforms (Facebook, Instagram, Twitter) accept JPEG, PNG, and WebP. JPEG is the safest choice because it's the smallest and works everywhere. If your image has a transparent background that you want to keep, use PNG instead.
Why is my PNG file so much larger than the JPEG?
PNG doesn't compress as much as JPEG. JPEG throws away some detail to make the file smaller, while PNG keeps all the detail. If file size matters, convert to JPEG or WebP instead, but understand that you'll lose some quality in the process.
Can I change the format of multiple photos at once?
Yes. On Mac, Preview can export multiple photos in one step. On Windows, you can use Paint's batch processing or read free tools like XnConvert, which converts hundreds of files at once. Online converters also let you upload multiple files, though they may have limits on how many you can convert per day.