How geohash works
A geohash interleaves the bits of longitude and latitude and writes them in base 32 (0–9 and b–z without a, i, l, o). Each extra character makes the cell 4 to 8 times smaller, and points that share a prefix are usually close together — which is why databases such as Elasticsearch, Redis and many ride-hailing systems use geohashes to index locations.
Cell sizes
| Length | Cell size (approx.) |
|---|---|
| 5 | 4.9 km × 4.9 km |
| 6 | 1.2 km × 0.6 km |
| 7 | 153 m × 153 m |
| 8 | 38 m × 19 m |
| 9 | 4.8 m × 4.8 m |
| 10 | 1.2 m × 0.6 m |
The decoded coordinates are the centre of the cell, and the converter shows the ± error. The Precision buttons set how many characters are generated (8 to 11).
A caveat about neighbours
Two points can be a metre apart and still have completely different geohashes if they sit on either side of a cell boundary (for example, across the equator or the Greenwich meridian). For proximity searches, query the cell and its eight neighbours.
Frequently asked questions
How do I decode a geohash?
Paste the geohash into the box. Its centre latitude and longitude appear, with the size of the cell.
How long should a geohash be?
Seven characters are about 150 m, nine are about 5 m. Choose the shortest length that is precise enough for your data.
Can geohash contain the letters a, i, l or o?
No. Geohash uses 32 symbols: the digits 0–9 and the letters b–z except i, l and o.