Ideal image sizes and formats for your posts
We all want our images to look as slick as possible on social media. There are a few tips to keep in mind to set yourself up for success.
In this article:
- Ideal image sizes for each social channel
- Saving your files and tips for best image quality
- Troubleshooting image orientation issues
Ideal image sizes for each social channel
The recommendations here focus on posting images specifically through your Buffer account. Posting through Buffer to a social network utilizes API services, which sometimes handle images differently than if you were to post natively on the social platform itself.
Image size requirements, formats, and automatic resizing
When uploading an image to Buffer, the image must be under 10MB. We currently support JPG, PNG and HEIC image files for all social networks except TikTok (which only supports videos), and additionally GIF files for X/Twitter, Facebook, LinkedIn, Instagram, Mastodon, and Pinterest.
Additionally, each social network’s API service has its own image file size limit (which may be different than the native upload limit). If the image you upload is under 10MB, but larger than the limit for that social network, we'll convert it to a smaller size to ensure it can be published. Only one image attribute (width or height) will be adjusted and the other will scale automatically. This ensures that the original aspect ratio will be kept.
📝 After uploading your images, you can resize them within the Buffer composer by following this guide: Editing your images in Buffer
Each file size limit is listed under the social network below. Please note, the file sizes listed below are specifically for static images, with GIF file requirements listed separately.
Jump to the relevant section below:
- X/Twitter
- TikTok
- Google Business Profiles
- Mastodon
- Threads
- Bluesky
| Minimum width | 320 (will be scaled up to the minimum if necessary) |
| Maximum width | 1440 (will be scaled down to the maximum if necessary) |
| Height | Varies, depending on width and aspect ratio |
| File format | JPG, PNG, WebP, HEIC |
| File size limit | 8MB |
| Minimum width | 320 (will be scaled up to the minimum if necessary) |
| Maximum width | 1440 (will be scaled down to the maximum if necessary) |
| Height | Varies, depending on width and aspect ratio |
| File format | JPG, PNG (PNG is recommended), WebP, HEIC |
| File size limit | 8MB |
| Aspect ratio | Must be within a 4:5 to 1.91:1 range or square |
📝 Important notes
- In order to use automatic publishing, your image must fall within the aspect ratio guidelines listed above. You can find guidance and more detail about aspect ratios here: Instagram's accepted aspect ratio ranges. If they fall outside of this aspect ratio, your post will be scheduled as a notification. Learn more in: Using notification based publishing for Instagram.
- If the image you upload is larger than 8MB, we'll convert it to a smaller size (1920 pixels wide) to ensure it can be published. The minimum dimensions accepted is 150 x 150 pixels. Smaller images will be scaled up to the minimum.
- Instagram carousel posts can be square, horizontal, or vertical in format — and can include both photos and videos. However, once the first photo or video is selected, all of the following photos or videos selected will be cropped to the same aspect ratio. i.e. For example, if the first photo you select is square (1:1) all of your following content will be cropped to a 1:1 format. This is a Instagram Carousel limitation, and happens when posting natively on Instagram and when publishing via Buffer. The first photo sets the cropping standard for the rest.
- If you want your image’s colors to look as true to the original as possible, it's important to save your images in the sRGB color profile, as this is the color profile that Instagram’s API supports. Please note that RGB is not the same as sRGB. Unfortunately, ProPhoto RGB color profile (the default color profile in Photoshop and Lightroom) is not supported by Instagram.
X/Twitter
| Supported file formats | JPG, PNG, GIF, WebP, HEIC |
| File size limit | 5 MB for static image 15 MB for animated GIF |
📝 Even if an image is within the file size limit, we will check that the image is smaller than 8192 x 8192 pixels, since this is X/Twitter's maximum allowed dimension. If it's bigger than that, your image will be resized to be just a little smaller.
Gifs on X/Twitter
If you see some quality loss or errors when creating your posts with animated GIFs, you can try these recommendations to improve success:
| GIF Maximum resolution | 1280 x 1080 (width x height) |
| GIF Maximum number of frames | 350 |
| GIF Maximum number of pixels (width * height * num_frames) | 300 million |
We support both image and document (PDF) scheduling to LinkedIn.
| Supported file formats | Number of files per post | Recommended image ratio | File size limit | |
| Images | JPG, PNG, WebP (images uploaded as WebP will be converted to PNG), HEIC, PDF | up to 9 images | 1200x627 | 10 MB |
| Document scheduling | 1 PDF | N/A | 100MB and 300 pages |
📝 Notes
- LinkedIn states that the optimal size for images to achieve consistency across various share methods, pages, and experiences, is 1200 x 627 pixels. This image size should prevent cropping and scaling across formats. That said, if you're looking to share the same image across multiple social networks (e.g. LinkedIn, Facebook, X/Twitter, and Instagram), we'd recommend using a square image to avoid cropping on LinkedIn.
An important note on padding and mobile display from LinkedIn:
“Images uploaded in the recommended 1200 x 627 ratio are automatically displayed on the mobile app with white padding on the top/bottom or sides of the image, to fit the ratio without being cropped. Although a 3:2 aspect ratio, or 1200 x 800, displays fully without padding, we recommend using the industry-standard 1200 x 627 ratio. Link share thumbnail image uploads are displayed in a 2:1 ratio. Limit text in rich media images to the center of the image in a title-safe area.”
| Supported file formats | JPG, PNG, GIF, WebP, HEIC |
| File size limit | 10MB |
TikTok
At this time, TikTok images are only supported on the web version of Buffer (TikTok image support in our mobile apps coming soon!).
| File size limit | up to 8MB |
| Format | JPG, webp (HEIC and PNG will be converted to JPG) |
| Maximum resolution | 1080 x 1920 pixels or 1920 x 1080 pixels |
| File size limit | 20MB |
Google Business Profiles
| File size limit | between 10Kb and 10 MB |
| Format | JPG, PNG, WebP (images uploaded as WebP will be converted to PNG), HEIC |
| Recommended resolution | 720px x 720px |
| Maximum resolution | 10,000px x 10,000px |
| Minimum resolution | 250px x 250px |
Mastodon
| File size limit | up to 8MB |
| Format | JPG, PNG |
| Recommended resolution | 1280px x 1280px |
Threads
| File size limit | up to 8MB |
| Format | JPG, PNG, WebP, HEIC |
📝 Notes
- Images (PNG, JPG, GIF, WebP, HEIC) up to 8MB are supported. Images will be downscaled to 1.6 megapixels (enough for a 1280x1280 image).
- Up to 4 images can be attached to one post.
- GIFs are converted to videos so only 1 GIF can be supported at a time.
- Animated GIFs are converted to soundless MP4s like on Imgur/Gfycat (GIFV). You can also upload soundless MP4 and WebM, which will be handled the same way. Learn more in the article: Attaching images, videos, and other media to your posts.
Bluesky
| File size limit | 1MB |
| Format | JPG, PNG, WebP, HEIC .HEIF |
📝 Notes
- Images for Bluesky must be under 1MB. We are unable to resize larger images at this time.
- GIFs must be under 15MB and 60 seconds in length.
Saving your files and tips for best image quality
When scheduling a post through Buffer, we send your image through API services that can handle files a little differently than if you were posting directly on the social channel yourself. This can cause some unexpected results if images are saved in certain ways, so we recommend using these tips if you are seeing distortion, pixelation, or slight color changes.
- Save your file in PNG (.png) file format, rather than .jpg or other file formats.
- Avoid transparent backgrounds as they can cause distortion.
- If possible, save in sRGB color mode, as this is what is used by most browsers and social networks. Try to stay away from other color modes such as AdobeRBG/CMYK. Not saving in sRGB will result in a slight change of image colors when published.
- Avoid overly large dimensions for images. If the image needs to be resized by Buffer or the social platform, it could impact the quality of the image.
Troubleshooting image orientation issues
Sometimes, images might appear to be rotated once they have been published to your social channel. When images are uploaded to Buffer, we use the orientation data that is hard-coded in the background of the image based on how it was taken or the tool used to process it. This background information is called the EXIF data. Whilst the image may appear to be the correct orientation when previewing it on your computer, or in the composer after uploading it in Publish, it might be rotated once published.
If this is happening for you, we thought we'd share this tool that can remove the EXIF data from images before uploading them. Upload your image and then click eXif.me. Check the box to the right of "EXIF Cleaner" that says "IF CHECKED ALL THE TAGS WILL BE CLEARED" and then click Go.eXifing. This will remove the EXIF data from your image and then you can download the image by clicking "Download.me".