IBM mainframe · CP037 · 8-bit

EBCDIC converter

Convert between ASCII and EBCDIC (CP037 / IBM-037), the 8-bit character encoding used on IBM mainframes. Non-ASCII-compatible bit layout means text must be explicitly transcoded when moving between platforms.

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How to use this tool

  1. Type or paste text into the ASCII text → EBCDIC (hex) box — the EBCDIC encoding appears instantly in EBCDIC hex as space-separated two-digit hex bytes.
  2. Hit Copy result to copy the encoded bytes to your clipboard.
  3. To reverse it, paste space-separated EBCDIC hex bytes into the EBCDIC hex → ASCII text box and the decoded text appears below it.
  4. Use Clear on either box to reset it and start over.
  5. Read each two-digit group in EBCDIC hex as one byte — for example C1 is A and F1 is 1 under CP037.

Why this tool is helpful

Read mainframe dumps

IBM z/OS logs, memory dumps, and data files hold EBCDIC bytes. Paste the hex here to see the plain text they represent.

Transcode legacy data

Moving records between a mainframe and a modern system requires an explicit ASCII ↔ EBCDIC conversion — this does it byte by byte.

Learn the code page layout

See why EBCDIC and ASCII are incompatible: letters sit at 0xC1–0xC9 and digits at 0xF0–0xF9, not the ASCII positions.

Debug fixed-width records

Mainframe records use fixed-width fields. Check the raw EBCDIC byte values behind each field to verify boundaries and content.

Verify character translations

Confirm that spaces, punctuation, and symbols map to the expected EBCDIC bytes before feeding data into a mainframe job.

Stay private

All conversion runs in your browser. Nothing is uploaded, logged, or sent to a server — safe for sensitive records.

FAQ

What is EBCDIC?

EBCDIC (Extended Binary Coded Decimal Interchange Code) is an 8-bit character encoding developed by IBM for its mainframes. Unlike ASCII, its bit layout is not ASCII-compatible, so text must be explicitly transcoded when moving between platforms.

How is EBCDIC different from ASCII?

Both are 8-bit, but they place characters at different code points. In CP037, letters A–I are at 0xC1–0xC9, J–R at 0xD1–0xD9, S–Z at 0xE2–0xE9, and digits at 0xF0–0xF9.

Which code page does the converter use?

The transcode applies CP037 (IBM-037), the standard US/Canada EBCDIC code page. The header also lists CP273 (Germany) and CP285 (UK) as related mainframe code pages, but the byte-for-byte mapping used here is CP037.

Why is the output space-separated hex?

Each EBCDIC character becomes one byte, shown as two hex digits. Spaces separate the bytes so you can read the value of each character at a glance, e.g. C1 C2 C3 for ABC.

What happens to characters outside ASCII?

Encoding is byte-oriented and built for CP037, which only defines printable characters in the ASCII range. Bytes above 0x7F are written as-is and may be mapped back through the CP037 table on decode, so keep input to standard ASCII text for reliable results.

Does any of my data leave my browser?

Never. All conversion happens locally in JavaScript. Your input is not sent to, stored on, or logged by any server.