Teclo vs Bucklespring
Updated
Bucklespring is the oldest keyboard sound program people still recommend: a free, open-source sampling of one IBM Model M, started in 2016. On a Mac you build it yourself and run it from Terminal. Teclo is a signed menu bar app whose Buckle pack imitates a buckling spring without sampling one.
1-day free trial · $4.99 once · up to 3 Macs · macOS 13+
Secure checkout, payments byStripe· 14-day refund, no questions asked
Pick a pack, then press any key or tap the keys below. These are the same samples the app plays.
Side by side
| Teclo | Bucklespring | |
|---|---|---|
| Price | $4.99 once | Free, open source (GPL-2.0)1 |
| Free trial | 1 day, no account | Not needed: free1 |
| Macs per licence | Up to 3 | Not listed |
| macOS | 13 or later | Not listed |
| Where to get it | Direct, at teclo.app, through Polar | Linux and FreeBSD packages; a community Windows build; on a Mac, built from source1 |
| Sounds | 16 packs in 5 categories, synthesized | One keyboard: a sampled IBM Model M1 |
| Press, release and variation | Separate press and release; 5 variants for ordinary keys plus Space, Return and Delete; small random pitch and level changes | Separate press and release for each key1 |
| Stereo by key position | Yes | Yes, each key placed in 3D1 |
| Mouse and trackpad | A click pair for every pack; trackpad swipe and pinch sounds | Not listed |
| Scroll sounds | Yes, optional | Not listed |
| Your own sounds | Yes: shape a pack with sliders, record one from the microphone or drop in WAV files; share it as a .teclo file | Loads WAV files from a folder1 |
| Muting | Pause from the menu bar; no per-app or automatic mute | Press Scroll Lock twice1 |
| Typing pet | Yes, a keycap pet with moods and power-ups | Not listed |
| Worth knowing | Rain, marimba, typewriter, arcade and sci-fi packs next to nine keyboards | A command-line program; last release v1.5.1 on 2021-10-282 |
- Bucklespring on GitHub, read October 2026
- Bucklespring releases, read October 2026
Teclo's column is ours. Other apps change their prices and features; check their pages before you buy.
The short answer
- Pick Bucklespring if you want a real sampled IBM Model M, free and open source, and you are at home building a program from source and running it with
sudoin Terminal. - Pick Teclo if you want an app you install by dragging it to Applications, with a menu bar icon, a volume slider, 15 more packs, mouse and trackpad sounds and a free 1-day trial.
One keyboard, sampled key by key
Ico Doornekamp wrote Bucklespring to emulate “my old faithful IBM Model-M space saver bucklespring keyboard”. Every key was sampled going down and coming up: the repository’s wav folder holds 209 files, and the program plays them back with OpenAL, “simulating the proper distance and direction” of each key. Command-line options set the gain, the stereo width and a folder of your own WAV files.
Teclo’s Buckle aims at the same board from the other side. It is synthesized: a snap over ringing steel, with a spectral centroid of 2,966 Hz and a 90 ms tail, brighter than every Teclo keyboard except Knuckle and Cricket. Ordinary keys rotate through 5 variants, Space, Return and Delete have their own sounds, and each key is placed in stereo by where it sits. Cricket, the clicky pack with a click jacket, is the nearest neighbour; play both above.
Running it on a Mac
Bucklespring is not a Mac app. Its README treats macOS as a rumour and gives five commands: install alure and pkg-config with Homebrew, clone the repository, relax a compiler flag, make, then sudo ./buckle &. It needs root to create its event tap, and Terminal needs Accessibility access, which lets Terminal do much more than listen. The last tagged release is from 2021, though the repository was still updated in August 2025.
Teclo asks for less: Input Monitoring for Teclo alone, used by a listen-only tap that cannot change a keystroke. The privacy guide explains the difference between the two permissions.
For the other free programs, see free keyboard sound apps for Mac, and Teclo vs Mechvibes for the cross-platform one with community packs. The linear, tactile and clicky guide puts Buckle next to the other switch types.
Questions
Does Bucklespring run on a Mac?
Its README says "I've heard rumours that bucklespring also runs on MacOS" and gives build steps with Homebrew and make. It needs superuser rights to create its event tap, and Terminal needs Accessibility access.
Is Bucklespring free?
Yes. It is open source under the GPL-2.0 licence. Its last tagged release, v1.5.1, came out on 2021-10-28.
Is Teclo's Buckle pack a recording of a Model M?
No. Teclo synthesizes all 16 packs. Buckle imitates a vintage buckling spring, "a snap over ringing steel"; it is not a sample of any one keyboard. Bucklespring is a sample of one.
How do I mute Bucklespring on a Mac keyboard without Scroll Lock?
Bucklespring mutes when you press Scroll Lock twice, and its -m option sets another key code for muting. Apple's keyboards have no Scroll Lock key, so on a Mac you would pick another key or stop the program.
Sources
Other facts on this page come from these pages, read on or before the date above.