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Convert CRX to RINEX online, or RINEX to CRX

Upload a Hatanaka-compressed .crx or .##d file and get plain RINEX back in seconds, or compress a RINEX observation file down to .crx for a smaller archive. No account, nothing to install.

Online CRX to RINEX Converter

Convert formats, change RINEX versions, or decompress Hatanaka files with no account required. Single-file conversion with instant header inspection.

Up to 20 MB per file · 10 free runs per day

Quick question, so we know you are a person

Runs on our server; the input is deleted as soon as the result exists and the outputs after one hour.

What Hatanaka (Compact RINEX) compression is

Hatanaka compression rewrites a RINEX observation file so that each epoch stores only its difference from the one before it, instead of the full value. The encoding is lossless in both directions: decoding a .crx or .##d file restores every observation value exactly as recorded, and RINEX 2 (.##d), RINEX 3, and RINEX 4 Hatanaka files are all handled, with the RINEX version preserved exactly as recorded.

What this converter does

  • Decompresses Hatanaka/Compact RINEX (.crx, .##d) back to plain, uncompressed RINEX (.rnx, .##o)
  • Compresses a plain RINEX observation file down to Hatanaka .crx for a smaller download or archive copy
  • Reads .gz and Unix-compress .Z wrappers automatically, so a .crx.gz or .21d.Z file decompresses in one step
  • Keeps the RINEX version exactly as recorded: nothing is upgraded or downgraded in the process
  • Free, no account: files up to 20 MB, 10 conversions per IP per day, with download links that stay live for 1 hour

When you need this

IGS, CORS, and most national GNSS archives distribute daily and hourly observation files as Hatanaka-compressed .crx or .##d to save bandwidth, but many processing tools only read plain RINEX. This page turns that archive download into plain RINEX in one upload or, going the other way, shrinks your own RINEX files with Hatanaka compression before you archive or re-upload them elsewhere. Batch conversion and files over 20 MB need a free account, which raises the per-file cap to 100 MB.

How to convert CRX to RINEX online

Decompress a Hatanaka-compressed .crx or .##d observation file to plain RINEX, or compress a RINEX file down to .crx, with nothing to install.

  1. Upload the .crx or RINEX file

    Select the compressed .crx / .##d file to decompress, or a plain .rnx / .##o file to compress. .gz and .Z wrappers are read automatically.

  2. Choose the operation

    Hatanaka decompress is selected by default; switch to Hatanaka compress to shrink a plain RINEX file down to .crx instead.

  3. Process in the cloud

    The converter decodes or encodes the file and keeps the RINEX version exactly as recorded: nothing is upgraded or downgraded.

  4. Download the result

    Download the converted file immediately; the link stays live for one hour.

What won't produce a result

Worth checking before you upload, so a run doesn't cost you credits to tell you what your data was missing.

A .crx file whose first header lines were edited, re-saved, or truncated by another tool before upload

The original CRX byte stream exactly as the archive or receiver produced it. Hatanaka decoding replays the differences between epochs in order, so an edited or truncated header breaks the decode partway through.

A navigation (broadcast ephemeris) or meteorological RINEX file

An observation file. Hatanaka compression only ever applies to RINEX observation data. Navigation and meteorological files are already small text and are never Hatanaka-compressed, so there is nothing here to decompress or compress.

Common questions

Is decompression lossless?

Yes. Hatanaka/Compact RINEX stores the differences between consecutive epochs rather than discarding data, so decoding a .crx or .##d file restores every observation value exactly as recorded. Compressing that output and decoding it again gives back an identical RINEX file.

What is the difference between .crx and .rnx?

A .rnx (or numbered .##o) file is plain-text RINEX with every epoch written out in full. A .crx (or .##d) file holds the same observations Hatanaka-compressed, storing only the differences between epochs, which is why archives distribute .crx files at a fraction of the size.

Can I compress RINEX back to CRX?

Yes. Choose "Hatanaka compress" above and upload a plain RINEX observation file, and the converter applies the same lossless encoding and returns a .crx file you can archive or re-upload elsewhere at a smaller size.

Why does my processing software reject .crx files?

Some GNSS software only reads plain, uncompressed RINEX and stops at the CRINEX VERS / TYPE header a Hatanaka file carries instead of a RINEX one. Decompress the .crx or .##d file here first, then feed the plain .rnx or .##o output to that software.

Standards & Specifications

A free account covers files up to 100 MB. No card required. View plans and usage costs

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