Your recordings.
An instrument kit.

Map notes and velocity, prepare each sample, and export a portable SFZ package with its WAV files.

From clips to a kit

Import up to 16 local audio clips, set root MIDI notes and key/velocity ranges, then automatically spread distinct roots inside each identical velocity band. Numeric MIDI notes are unambiguous; Tesskey labels note 60 as C4. Filename root suggestions can be edited. Pitch is not detected.

Trim and apply short fades; optionally normalize peak level to −1 dBFS. Listen to processed sources at their original pitch. Check invalid ranges, overlaps and uncovered velocities. Intentional layering requires an explicit setting. Save, reopen, rename, duplicate and delete local kits, including source copies and notes.

Real delivery files

The ZIP contains instrument.sfz, processed 16-bit PCM WAVs in Samples, Mapping.csv, Settings.json and Readme.txt. Unzip the entire folder before loading instrument.sfz in a compatible sampler. Sample paths are relative to the SFZ file. Settings.json records edits and mapping; processed WAVs are not an original-source backup.

Limits

Mono/stereo audio iOS can decode, 0.05–30 seconds per clip, 8–192 kHz, up to 64 MB and two million decoded channel samples. 16 samples per kit, 64 MB maximum exported ZIP. Preserve source channel count and sample rate in WAV. Basic SFZ key/root/velocity and one_shot or no_loop instructions. Host behavior can vary. No pitch detection, audio recording, effects, loop editing, transposed keyboard player, MIDI controller, AUv3 or SF2/NKI import. The optional synthetic example contains generated plucks, not instrument recordings.

Support

Email maga40@naver.com with your app version, device, audio format, clip duration, sample rate and the action that failed. For playback issues include the destination SFZ host. Send audio or exported files only if you intentionally choose to do so.

Privacy policy

Effective October 1, 2026. Gobling Company provides Tesskey. The app has no account, advertising, analytics, tracking or third-party data SDK. It does not collect or transmit audio, names, notes, mappings or exports to a developer server. Processing and storage are local.

Only audio you select through Files is imported. Kits retain local source copies, names, notes and edit/mapping settings. The library starts empty; the optional synthetic example is labeled.

System sharing sends the ZIP you select to your chosen destination. The ZIP includes processed audio, sample and kit names, notes and settings. Review it before sharing; destinations have their own privacy practices.

Deleting a sample or kit removes its app-local source and settings; uninstalling removes app-local data. Previously exported and shared copies remain at their destinations and must be deleted there. Device backups may include local data according to Apple/computer settings. Keep separate backups of original audio and saved exports.

Support receives information you choose to email. Visiting this website makes ordinary requests to its hosting provider. Neither is required for local mapping or export.

Terms of use

Process and distribute only audio you have the right to use. Check note/velocity mappings, audio quality and destination host behavior before delivery. Tesskey does not guarantee universal sampler compatibility or musical pitch accuracy. Keep separate original-source backups. Purchases follow App Store terms and applicable law.