Choose PNG frames, a GIF or a sprite atlas

Understand the three exports, generic JSON coordinates, alpha transparency and playback timing.

Choose GIF to share a playing preview, PNG frames to keep separate images, or an atlas to pack the edited frames into one image. FrameMint exports all three from the same frame order, positions and color-key settings. Preview overlays and the checkerboard are never included in exported pixels.

PNG sequence: one image per edited frame

The PNG ZIP contains frame_001.png, frame_002.png and so on, plus timing.json and a README. All images use the same width and height and preserve full alpha transparency. The timing file lists each image’s duration in milliseconds, the playback mode and a zero-based playback order. Ping-pong is represented in that order rather than by duplicating PNG files.

Atlas: one sheet and its coordinates

The atlas ZIP contains framemint-sheet.png, framemint-atlas.json and a README. Choose the number of columns. Cells are filled left to right, then top to bottom, following your edited order. Empty cells at the end are transparent. Coordinates start at the top-left of the image. The JSON records x, y, width, height, duration and source frame number for each cell.

This is a generic documented JSON format, not a Unity, Godot or Phaser import preset. Set up the import for your engine and check its coordinate convention. For example, the third 64 × 64 frame in a four-column atlas has x = 128, y = 0. The fifth has x = 0, y = 64. See the Godot sprite animation documentation for an example of creating animations from separate images or a sprite sheet.

GIF: convenient playback, reduced color information

GIF is useful for messages and previews. It uses a palette and on/off transparency, so a glow with partial alpha may lose its soft edge. Timing is rounded to 10 ms. Browser players may handle animation timing differently. Use PNG for an asset master and inspect the GIF as a separate output.

Export scale and limits

100% keeps the cell’s original pixel dimensions. Other scales use nearest-neighbor resizing, which is appropriate for crisp pixel edges but can be harsh on painted art. GIF is limited to 1024 pixels per side and 32 million total output pixels across its playback sequence. PNG frames have a 4096-pixel side limit and the same total-pixel budget. An atlas additionally must fit within 8192 pixels per side and 16 megapixels including unused cells. Choose a smaller scale when a limit is reached.

FrameMint processes exports on your device. A successful download action means a file was handed to the browser; it does not prove a game-engine import succeeded. Keep your original artwork and verify the exported sequence before replacing assets in a project.

By Draconova · Updated 14 September 2026. This guide describes the current tool; use the preview and check your downloaded output.