KiiMix Free Online Image Tools
Compress batches, crop photos or resize images with a preset. These tools are free, run locally in your browser and export JPEG. Your image files are not uploaded.
How to choose
Reduce file size
Lower JPEG quality to make a file smaller. Check the result after processing: the same quality setting produces different file sizes for different images.
Change the crop or aspect ratio
Drag the crop box to keep the part you want, or choose a preset ratio. Check the preview before exporting.
Prepare a social media image
Compare presets for YouTube, Instagram, X, Xiaohongshu and TikTok. Each tool page lists its export size and explains the relevant platform guidance.
General tools
Social platform sizes
YouTube thumbnail cropper
Crop a 16:9 YouTube thumbnail. Export a 3840 × 2160 JPEG.
Open toolInstagram post cropper
Crop an Instagram post to 4:5. Export a 1080 × 1350 JPEG.
Open toolInstagram Story cropper
Crop a 9:16 Instagram Story. Export a 1080 × 1920 JPEG.
Open toolX / Twitter image cropper
Crop a landscape X / Twitter post image to 1200 × 628.
Open toolXiaohongshu cover cropper
Crop a 3:4 Xiaohongshu cover. Export a 1242 × 1656 JPEG.
Open toolTikTok cover cropper
Crop a 9:16 cover image. Export a 1080 × 1920 JPEG.
Open toolFormats and file limits
These image tools process files in your browser. You can add up to 12 images, each no larger than 20 MiB. All results are JPEG, with transparent areas filled white. Keep the original PNG if you need a transparent background. Enlarging an image will not restore missing detail.