ExpressLRS 4.0 Is Here — Don't Flash Until You Read This (Compatibility Warning Inside)
Major release. New packet rates. Better range in RF-cluttered bando environments. But some older hardware will break. Here's the full picture.
Why ELRS Changed Everything
ExpressLRS is one of the best things that happened to FPV. Open source, fast, long range, runs on cheap hardware, and beats proprietary systems that cost three times as much. Version 4.0 is the biggest release since 3.0 — with meaningful improvements alongside compatibility changes you need to understand before you touch the flash button.
What's New in ELRS 4.0
📡 New Packet Rate System
50Hz Full Resolution mode is now the recommended baseline for freestyle. It delivers cleaner telemetry data and improved link resilience while keeping latency at the same level as previous versions. If you log your flights or use GPS tracking, this alone is a reason to update.
🏗️ Better Range in RF-Cluttered Environments
Range in urban environments improved measurably. For bando flying — industrial zones, concrete structures, anything with metal — the link holds better at the edges. Not a massive change, but noticeable when you're threading gaps 200m out in a complex structure.
🏙️ Bando pilots specifically benefit here. Urban RF environments are the hardest conditions for any radio link. ELRS 4.0's improvements are most visible exactly where most freestyle pilots push their limits.
⚠️ What Might Break
⚠️ Some older ESP8266-based hardware — early Happymodel modules from pre-2023 — won't fully support the new packet modes. Check the ELRS 4.0 supported hardware list on GitHub before touching anything.
The binding phrase system carries over correctly from 3.x. But don't assume — test one quad before updating your entire fleet.
The Only Safe Upgrade Sequence
- Check the ELRS 4.0 supported hardware list on expresslrs.org before touching anything.
- Update your TX module first, verify it connects to ELRS Configurator correctly.
- Update receivers one by one, rebind and test each before moving to the next.
- Never update everything the evening before a flying session.
✅ Building a new quad from scratch? Start with ELRS 4.0 directly. No reason to begin with an older version when building fresh.
The Frame Pairing That Makes ELRS Shine
A reliable radio link is only part of the equation. The frame's geometry and carbon quality determine how clean your gyro data is — which determines how well ELRS telemetry translates into a dialed-in tune. We've been flying ELRS since before it was mainstream, and every major version has been worth the upgrade.
Pair ELRS 4.0 with a frame that was built for the environments where ELRS matters most. The Ferrum 50's 7mm arms survive the crashes that happen when you're pushing range limits in tight urban spots. Available in Black, White, and Purple.
→ Shop Ferrum 50