How the tool works
Choose a JPEG, PNG, or WebP image, select an Instagram preset or enter custom dimensions, and decide whether to crop, fit, or stretch it. Reposition and zoom the image in the live preview before exporting the final file.
Supported input and output
The tool reads and exports JPEG, PNG, and WebP. JPEG and WebP include a quality control, while PNG preserves transparency. The first presets cover square posts, portrait posts, and Stories or Reels.
Practical example
Turn a 1920 × 1080 landscape photo into a 1080 × 1350 portrait post. Crop mode fills the frame, and dragging the preview keeps the subject inside the visible area.
Common use cases
Prepare posts, Stories, Reels covers, profile graphics, campaign assets, and exact-size images without opening a desktop editor. Custom dimensions also work for platforms not yet included in the preset list.
Limits and important checks
Enlarging a small source can make it look soft. Stretch mode can distort proportions, and lossy formats may introduce compression artifacts. Platform recommendations can change, so verify critical campaign requirements.
Privacy and local processing
Unless the tool explicitly identifies an external lookup, input and generated output are processed in your browser and are not uploaded to CosmoTools. Avoid placing secrets in any web page and review downloaded results before using them in production.
Frequently asked questions
Is my image uploaded?
No. Loading, resizing, previewing, and exporting happen locally in your browser.
Which image formats are supported?
You can open and export JPEG, PNG, and WebP images.
What is the difference between crop and fit?
Crop fills the frame and trims overflow. Fit keeps the entire image and adds space where the proportions differ.