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The Best Open-Source Alternatives to Bolt

Are you looking for a free or self-hosted alternative to Bolt? In 2026, avoiding expensive proprietary software subscriptions is easier than ever. The open-source community has built excellent privacy-friendly tools within the Payments ecosystem. Currently, there are 6 active replacements available, with Zephyr being one of the most prominent selections.

Quick Comparison: Bolt vs. Open Source

Full comparison: Bolt vs. Zephyr →
CriteriaBoltOSS Replacements
Pricing modelPaid / Monthly Fees100% Free / Self-Hosted
Data ControlThird-party ServersFull Ownership & Privacy
CustomizabilityRestricted by VendorUnlimited (Modify Codebase)

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Zephyr

šŸ“ˆ Trending⭐ 10k+ Stars
Apache-2.0

Zephyr is a highly configurable, open-source Real-Time Operating System (RTOS) that provides a secure, flexible platform for building reliable software across various embedded systems, offering a privacy-friendly alternative to proprietary solutions like Bolt. Its modular design and rich ecosystem make it an ideal choice for industries seeking secure, customizable firmware without compromising on data sovereignty.

⭐ 16,043 Stars
šŸ“ 9,638 Forks
ā— 0 Open Issues
šŸ·ļø Apache-2.0
NOASSERTION

Tock is a highly configurable, kernel-based real-time operating system designed for resource-constrained devices, providing a secure and private alternative to Bolt for low-level device management. By leveraging a modular architecture and a focus on data minimization, Tock serves as an ideal choice for developers prioritizing privacy and security in their IoT and edge computing projects.

⭐ 6,397 Stars
šŸ“ 850 Forks
ā— 0 Open Issues
šŸ·ļø NOASSERTION
LGPL-2.1

RIOT (Routing Internet of Things) is a widely-used, open-source operating system for IoT devices focused on secure, reliable networking and low-power consumption, making it an attractive alternative to proprietary solutions like Bolt. Its open nature and commitment to user privacy ensure that developers and users have full control over their IoT data and configurations.

⭐ 5,765 Stars
šŸ“ 2,108 Forks
ā— 0 Open Issues
šŸ·ļø LGPL-2.1

FreeRTOS is an open-source, real-time operating system kernel that enables efficient, lightweight, and secure embedded system development, making it an ideal alternative to proprietary solutions like Bolt for projects requiring robustness and reliability. As a free and community-driven project, FreeRTOS offers unparalleled transparency and flexibility to developers, ensuring their code remains private and secure.

⭐ 4,390 Stars
šŸ“ 1,584 Forks
ā— 0 Open Issues
šŸ·ļø MIT
Apache-2.0

NuttX is a highly configurable, real-time operating system (RTOS) designed for embedded and IoT devices, offering a lightweight, secure, and reliable alternative to traditional RTOS solutions like BOLT, while prioritizing data privacy and user control. As a drop-in replacement, NuttX enables developers to create connected devices with a strong focus on user data protection and customization.

⭐ 3,971 Stars
šŸ“ 1,639 Forks
ā— 0 Open Issues
šŸ·ļø Apache-2.0
Apache-2.0

Mynewt is a secure, modular, and highly customizable operating system designed for resource-constrained IoT devices, offering a trusted and privacy-friendly alternative to proprietary solutions like Bolt for building secure, connected devices. By leveraging its open-source nature and flexibility, developers can create tailored firmware for a wide range of IoT use cases.

⭐ 889 Stars
šŸ“ 382 Forks
ā— 0 Open Issues
šŸ·ļø Apache-2.0

Frequently Asked Questions

What is the best open source alternative to Bolt?

Based on GitHub community data (including star count and fork activity), Zephyr stands out as one of the most reliable open-source replacements for Bolt today.

Why should I use an open-source replacement instead of Bolt?

Switching to an open-source solution ensures complete data sovereignty, protects your software environment from sudden vendor price hikes, and gives you full transparent control over your tech-stack metadata.