Plus Codes Converter | Round-Trip OLC and Lat/Lng in the Browser

Convert Plus Codes (Open Location Code, OLC) to lat/lng and back, with 10, 11, or 12-digit precision. The result panel shows the matching grid cell's SW and NE corners and the real cell size in metres, with cosine correction applied so the figures stay honest near the poles. The tool implements the OLC algorithm from scratch — no 300+KB open-location-code library is loaded.

💡 About this tool

Plus Codes are a clean alternative to street addresses when a place has no number — a hiking shelter, a stall at a temporary market, a meeting point at a port. They are also the shape of code you see scattered around Google Maps URLs like https://plus.codes/8FW4V75V+8R. The reverse problem — taking a code out of a chat or email and getting the lat/lng back — is more common than the docs suggest, and the official decoder page is a few too many clicks for a quick paste.

This tool puts both directions on the same screen. Toggle the mode, paste a value, and the matching code or coordinates appear. Change precision and you see how the cell size really behaves: roughly 14 m × 14 m at 10 digits, ~2.8 m × 3.5 m at 11, and a 0.6 m grid at 12. The metric output applies latitude cosine correction (111,320 × cos(lat) metres per degree of longitude), so the equator and Stockholm look very different — and they should.

Validation follows the OLC spec: only 23456789CFGHJMPQRVWX is accepted, separator position is checked, and padding 0 patterns are validated. Lowercase input and stray spaces are normalised silently, so pasting 8fw4v75v+8r works.

🧐 Frequently Asked Questions

Q. How do I pick between 10, 11, and 12 digits? 10 digits gets you to roughly the front door of a building. 11 digits is parking-bay or stall scale — useful for event entrances and pickup spots. 12 digits is a 0.6 m square, fine-grained enough to point at the base of a statue or a specific crack in the pavement, though it exceeds the absolute accuracy of consumer GPS.

Q. Will any Plus Code from Google Maps work here? Yes, full codes do. Paste the part after plus.codes/ (for example 8FW4V75V+8R), or copy the code from a Google Maps place card. We normalise case and whitespace internally, so you don't have to tidy it first.

Q. What about shortened codes like 75V+8R? We accept full codes only. A shortened code needs a reference location to make sense — without that the same fragment could land in dozens of different places worldwide. Reconstruct the full code in Google Maps before pasting it here.

Q. Does this work at the poles and across the date line? It does. Latitude 90° is clipped to 90 − ε per the OLC spec, and longitudes outside [−180, 180) are wrapped before encoding. Grid-digit math uses integer floor / modulo over base-20, so values near the seams stay stable.

Q. Is the cell size an estimate of GPS accuracy? No. The cell size is a property of the code itself — the bounding box it represents on a sphere. Consumer GPS receivers usually land within 3–10 m, so claiming "12-digit codes give 60 cm accuracy in the field" mixes two different things. Treat the cell as a label, not a calibration target.

📚 Fun Facts

Open Location Code was published by Google's Zurich office in 2014 and released under Apache 2.0, which is why you'll spot it in postal pilots from India to Cape Verde rather than tied to one product. India Post once published a guide encouraging rural recipients to share Plus Codes when their addresses defaulted to a village name.

The 20-character alphabet 23456789CFGHJMPQRVWX is the bit OLC nerds geek out about. The selection avoids visually confusable glyphs (0 vs O, 1 vs I/L, B vs 8), and was tuned for legibility on cheap printers and in voice — yes, voice. Plus Codes were designed to be dictated over the phone in regions where typing addresses is harder than reading them out.

The structure itself is a hybrid: five base-20 pairs for the "address" part, then base-4-by-5 grid digits for refinement. That layout lets the first eight characters land you in the right village and additional digits zoom in without ballooning the string length, which matters more than it seems when codes are printed on van side panels or scribbled on hand-drawn maps.