Does HMAC-SHA256 upload my file or text to Tool-You servers?

No. HMAC-SHA256 runs in this browser tab. Files stay on the device. Limit note: Non-empty key and message. Optional uppercase hex.

Should I use Hash Text instead of HMAC-SHA256?

Use HMAC-SHA256 when you need HMAC-SHA256 hex and Base64; optional uppercase. Use Hash Text when you need Hash text with SHA-2, SHA-1, or MD5. They share a category (Crypto) but not the same job.

HMAC-SHA256

HMAC-SHA256 hex and Base64; optional uppercase.

Keyed SHA-256 of the message. Optional uppercase hex. Unlike SHA-256 Digest this requires a key. Empty key or message fails. Local only.

What HMAC-SHA256 does

Keyed SHA-256 of the message. Optional uppercase hex. Unlike SHA-256 Digest this requires a key. Empty key or message fails. Local only.

The interactive controls for HMAC-SHA256 load after this article so crawlers still read the instructions. Path /crypto/hmac-sha256 is the canonical address. Work happens on this device; Tool-You does not take a copy of the file or pasted text for HMAC-SHA256.

How to use HMAC-SHA256

Keep this tab on HMAC-SHA256 (/crypto/hmac-sha256). Pasting into the wrong Crypto tool (for example Hash Text) changes the job.
Paste or type the input HMAC-SHA256 expects. Path hint: crypto · hmac sha256. HMAC-SHA256 hex and Base64; optional uppercase.
Apply the HMAC-SHA256 action only. Encrypt Text is a different transform (AES-GCM encrypt or decrypt text.). Keyed SHA-256 of the message. Optional uppercase hex. Unlike SHA-256 Digest this requires a key. Empty key or message fails. Local only.
Copy the output of HMAC-SHA256 if you need it elsewhere. Size/complexity still follows: Non-empty key and message. Optional uppercase hex.
If the text job is actually Hash text with SHA-2, SHA-1, or MD5., leave HMAC-SHA256 and open Hash Text.

When not to use HMAC-SHA256

Skip HMAC-SHA256 when a neighbor tool matches better — start with Hash Text or Encrypt Text — or when the description already warns the job will fail. In the tool’s own words: Keyed SHA-256 of the message. Optional uppercase hex. Unlike SHA-256 Digest this requires a key. Empty key or message fails. Local only.

Questions about HMAC-SHA256

What does HMAC-SHA256 do that other Crypto pages on this site do not?: Keyed SHA-256 of the message. Optional uppercase hex. Unlike SHA-256 Digest this requires a key. Empty key or message fails. Local only. Short version: HMAC-SHA256 hex and Base64; optional uppercase.
Does HMAC-SHA256 upload my file or text to Tool-You servers?: No. HMAC-SHA256 runs in this browser tab. Files stay on the device. Limit note: Non-empty key and message. Optional uppercase hex.
Should I use Hash Text instead of HMAC-SHA256?: Use HMAC-SHA256 when you need HMAC-SHA256 hex and Base64; optional uppercase. Use Hash Text when you need Hash text with SHA-2, SHA-1, or MD5. They share a category (Crypto) but not the same job.
What are the limits of HMAC-SHA256?: Non-empty key and message. Optional uppercase hex. Also: Keyed SHA-256 of the message. Optional uppercase hex. Unlike SHA-256 Digest this requires a key. Empty key or message fails. Local only.