Download a GeoTIFF by coordinates: a base map for exactly the area you need

You need a GeoTIFF for exactly your plot — by specific coordinates rather than "roughly this city" — and you want the file to land in the right place in QGIS by itself. That comes down to four decisions: the area bounds, the coordinate system, the resolution and the style. Let's go through each, plus how to open such a file and how to make sure the georeferencing survived.

What a georeferenced raster is

A GeoTIFF is an ordinary TIFF with service tags written inside: which coordinate system the image lives in, how many metres (or degrees) one pixel covers, and where on Earth the anchor corner sits. Thanks to those tags, a GIS program opens the file and immediately places it correctly on the map, with no manual georeferencing.

A plain PNG or JPEG has no such tags — their georeferencing is kept in a separate sidecar text file (.pgw for PNG, .tfw for TIFF). Lose it and you lose the georeferencing. In a GeoTIFF everything sits in one file, which is why GIS work uses it.

An important caveat: a base map and a satellite image are different things. What follows is about a raster rendered from OpenStreetMap data (roads, buildings, water, greenery). For imagery and remote sensing, see GeoTIFF in remote sensing; for terrain elevation, see SRTM and GeoTIFF without USGS.

Step 1. Set the area by coordinates

The plot bounds are described by four numbers — a bbox: minimum longitude, minimum latitude, maximum longitude, maximum latitude. The order reads as "west, south, east, north", and the values are in WGS 84 degrees (the very ones your GPS shows).

An example for central Berlin: 13.39, 52.51, 13.42, 52.53. Such an area can be passed straight in the link:

https://osm2cdr.ru/?format=geotiff&bbox=13.39,52.51,13.42,52.53

Two common mistakes: swapping latitude and longitude (GPS usually writes "latitude, longitude" while a bbox is the other way round), and forgetting the minus sign for the western hemisphere and southern latitudes.

Step 2. Choose the coordinate system

This is the CRS that gets baked into the file, and it decides whether the raster lines up with your layers:

• EPSG:4326 (WGS 84) — degrees. Universal, but the pixel isn't square in metres and measuring areas and distances is awkward.
• EPSG:3857 (Web Mercator) — the web-map standard, handy if tiles will sit on top.
• A UTM zone (32633 for Berlin, say) or a local metric grid — the right choice when measurements are coming.

A simple rule: export in the same CRS your QGIS project lives in, otherwise the program reprojects the raster on the fly and drags. A breakdown of coordinate systems is in the EPSG guide.

Step 3. Choose the resolution

Resolution is set through DPI and image width in pixels, and the meaningful figure comes from a division: the area width in metres divided by the number of pixels.

• a 2 km plot at 4000 pixels wide — 0.5 m per pixel, individual buildings are visible;
• a 10 km plot at the same 4000 pixels — 2.5 m per pixel, fine for an overview underlay;
• for print take 300 DPI; for screen and web 96-150 DPI is enough.

Remember that file size grows as a square: double the pixel width and you quadruple the size. A raster city map easily reaches hundreds of megabytes.

Step 4. How to open it

• QGIS — Layer → Add Layer → Add Raster Layer, the georeferencing is picked up automatically.
• ArcGIS Pro, Global Mapper, MapInfo, SAGA — open it natively.
• Windows and macOS viewers will show the picture but say nothing about coordinates — that's normal.
• Photoshop opens the TIFF but on re-saving almost certainly drops the geo tags: after editing there, the file stops being a GeoTIFF.

Step 5. Verify the georeferencing

Three quick checks:

1. In QGIS: Layer Properties → Information — it lists the CRS, the extent and the pixel size. If the extent shows zeros or nonsense, the tags aren't there.
2. On the command line: gdalinfo file.tif prints Coordinate System, Pixel Size and the corner coordinates.
3. Visually: switch on any layer with known geometry (boundaries, roads) on top and see whether they match.

If the raster is offset by a constant amount, it's almost always a mixed-up CRS rather than the file itself.

Easier — get a ready file straight away

Set the area and download it straight as GeoTIFF — with the coordinate system you chose and the resolution you need, ready to drop into QGIS. If georeferencing isn't needed and the file goes into a report or a presentation, take PNG; for print work, TIFF. It's free and takes seconds. A technical breakdown of the format is in the GeoTIFF deep dive.

In short

• GeoTIFF = TIFF plus tags with the CRS, pixel scale and anchor point; georeferencing lives inside the file.
• The area is set by a bbox: west, south, east, north in WGS 84 degrees.
• Pick the CRS to match your project: 4326 for degrees, 3857 for web, UTM or a local grid for measuring.
• Resolution is "metres per pixel": 2 km / 4000 px = 0.5 m.
• Verify with layer properties in QGIS or gdalinfo file.tif.
• Photoshop kills the geo tags on re-save; for a base map take GeoTIFF directly.