JNEXT review
A free desktop emulator for ZX Spectrum software, peripherals, recording, and reverse debugging.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
JNEXT is a free, open-source desktop emulator for ZX Spectrum 48K, 128K, +2A/+3, and ZX Spectrum Next software. It is aimed particularly at developers working with ZX Spectrum Next projects, while also supporting general software playback. Packages are provided for Windows, macOS, and Linux. The emulator loads NEX, SNA, SZX, Z80, TAP, TZX, WAV, and RZX files, supports fast and real-time cassette loading, and can boot NextZXOS from an SD-card image.
Its standout capability is the built-in debugging environment. JNEXT provides CPU, memory, video, sprite, Copper, NextREG, and audio views, along with execute, read, write, and I/O breakpoints. It can record instruction traces and supports backward execution, giving developers tools for investigating program behavior rather than simply running software. Video, WAV audio, and RZX recording are also available for documenting or reviewing sessions.
The emulator also covers a substantial range of peripherals, including DivMMC, SD card, Multiface, DMA, UART, CTC, SPI, I²C, and a real-time clock, plus keyboard, USB gamepad, Kempston mouse, and ESP-01 WiFi module support. JNEXT is a strong fit for ZX Spectrum Next development, debugging, and preservation workflows that benefit from detailed machine inspection. Casual players may find its debugging depth unnecessary, and its scope remains centered on ZX Spectrum machines across desktop operating systems.
JNEXT pros and cons
- Where it wins
- Supports ZX Spectrum 48K, 128K, +2A/+3, and Next machines
- Built-in debugger includes CPU, memory, video, sprite, audio, and NextREG views
- Loads broad program, tape, snapshot, and recording formats
- Where it doesn't
- Focused on ZX Spectrum systems rather than broader computer platforms
- Advanced debugging may be more than casual players need
- Desktop support is limited to Windows, macOS, and Linux
JNEXT fact sheet, pricing and score →
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