Merge multiple raster files into a single mosaic
Automatic mosaic by coordinates
Files processed in browser
Handles overlapping areas, keeps valid data
Upload at least 2 raster files
Raster Merge stitches multiple rasters into a single mosaic automatically: it reads each file's georeferencing, computes the union extent, aligns the grids, and fills the output with valid pixels from every input. Files can be added one by one or imported as a whole folder, and the entire mosaicking job runs locally in your browser - free and private.
It is built for tiled deliveries: joining provincial map sheets into a national raster, combining drone flight blocks into one orthophoto, or assembling per-region model outputs into a single layer ready for the next analysis step.
Select two or more rasters - drag in a batch of files or import an entire folder; every file is listed on screen before processing begins.
Start the merge: the tool unifies the cell size to the coarsest input, computes the combined extent, and writes valid pixels into the mosaic - guarding against outputs beyond 20,000 x 20,000 cells.
Download the single mosaic file that replaces the pile of tiles, with nodata pixels preserved as gaps.
AThe first file that places a valid pixel at a location wins; later files only fill cells that are still nodata. Nodata areas inside earlier inputs therefore let later inputs show through, so order your files with the most reliable coverage first.
AMixed resolutions are fine - the mosaic adopts the coarsest cell size among the inputs and aligns the rest. The coordinate systems must match, however, so reproject any outliers first, and use inputs with the same band count so pixel values can be combined.
AThe merged grid is capped at 20,000 by 20,000 cells to keep browser memory in check. If your files exceed it, merge them in groups or clip the inputs to the area of interest first to remove wasted pixels.