The Ultimate Guide to Finding a Small, Custom ROM-Friendly Smartphone in a Large Phone Market

Your trusted Samsung Galaxy S10e, with its bespoke custom ROM, is reaching the end of its lifecycle. This scenario is all too familiar for enthusiasts who value compact form factors and the unparalleled freedom of a customized Android experience. The search for a spiritual successor—a small phone with an active development scene for custom ROMs like LineageOS, Pixel Experience, or MIUI-based builds—is indeed like searching for a needle in a haystack. The market is saturated with massive phablets, and manufacturers are increasingly locking down bootloaders, making the quest for a pocketable, open-device more challenging than ever.

We understand this struggle intimately. Over the past seven years, we have analyzed thousands of devices, tracked kernel sources, and monitored developer communities. We have curated this comprehensive guide to navigate the current landscape, analyze the top contenders, and help you identify the perfect small-form-factor smartphone that begs to be customized.

Understanding the Modern Smartphone Landscape for Custom ROM Enthusiasts

Before diving into specific recommendations, it is crucial to understand why this search is so difficult. The definition of a “small phone” has changed drastically. In 2024, a compact device is generally defined as having a screen size between 5.8 inches and 6.4 inches, with a width of less than 72mm to ensure comfortable one-handed use.

The Decline of the Compact Flagship

Manufacturers have largely abandoned the compact flagship segment. The reasons are twofold: battery life limitations due to smaller chassis constraints and consumer demand for larger media consumption screens. Consequently, most compact phones released today are mid-range devices, which often lack the powerful SoCs or the developer support needed for a vibrant custom ROM scene.

The Importance of Bootloader Unlocking

The ability to flash a custom ROM is entirely dependent on one factor: Bootloader Unlocking. Not all phones support this, and those that do often impose strict conditions.

• Google Pixel: Offers the easiest bootloader unlock process with the most extensive custom ROM support.
• Xiaomi: Requires applying for an unlock permission via their Mi Unlock Tool, which enforces a waiting period (often 72 hours to 30 days).
• Samsung: Exynos variants (Global) are generally easier to unlock, while Snapdragon variants (US/China) are notoriously locked and bootloader unlocking is often impossible or highly restricted.
• Sony: Traditionally very developer-friendly, though their compact line has been discontinued recently.

Analysis of the Top Contenders: The Search for the S10e Successor

Based on your query and the current market, we have identified a specific set of criteria: Screen Size (<6.4"), Performance (Snapdragon 8 Gen 2 or equivalent), and Developer Support (High). Let’s analyze the phones you mentioned and explore other worthy alternatives.

Google Pixel 7 / Pixel 8: The Gold Standard for Software and ROM Support

You correctly identified the Google Pixel 7 (and its successor, the Pixel 8) as having “a lot better software.” For the custom ROM community, the Pixel line is the undisputed king.

Why the Pixel Series Dominates Custom ROMs

The Pixel development scene is thriving because Google provides the cleanest source code and the most robust hardware abstraction layers.

• GrapheneOS & CalyxOS: If privacy is your priority, these security-hardened Android derivatives are exclusive to Pixel devices.
• Pixel Experience & LineageOS: These offer the purest Android experience, often with better performance than stock because they remove Google’s bloatware.
• Kernel Source Availability: Google releases kernel sources almost immediately, allowing developers to optimize performance and battery life efficiently.

The Form Factor Reality Check

The Pixel 7 features a 6.3-inch display, while the Pixel 8 reduced this to 6.2 inches. The Pixel 8 Pro is massive. However, the bezels on the Pixel 7 are slightly larger than modern standards, giving it a footprint that feels a bit bulkier than the legendary S10e. If you prioritize software stability and long-term support (guaranteed 7 years of updates on the Pixel 8), this is the safest bet.

Xiaomi 13 / 14: The Hardware Powerhouse with a Compromise

You noted that “hardware wise is the closest to it is Xiaomi 13.” This is absolutely correct. The Xiaomi 13 (and the newer Xiaomi 14) is a true compact flagship with top-tier specs that rival large gaming phones.

Hardware Superiority

The Xiaomi 13 packs a Snapdragon 8 Gen 2, a Leica-tuned camera system, and incredibly fast charging (67W wired, 50W wireless) into a body that is even narrower than the Pixel. From a hardware perspective, it is the S10e’s true heir. However, the software journey is different.

Navigating the MIUI/HyperOS Custom ROM Scene

To customize a Xiaomi device, you must navigate the Xiaomi.eu ROM community.

1. Unlocking: You must request unlock permission from Xiaomi and wait out the timer.
2. Development: The MIUI (now HyperOS) source code is dense. While there are incredible custom ROMs available (like MIUI.eu or various AOSP builds), they often lag behind official OS updates compared to Pixel builds.
3. Complexity: Flashing a Xiaomi device often requires more steps, including handling dynamic partitions (AB partitions) and specific firmware versions.

If you want raw performance and hardware features (like the telephoto lens and fast charging) in a small package, and you are willing to put up with a slightly more complex flashing process, the Xiaomi 13/14 is a formidable contender.

Samsung Galaxy S23: The Established All-Rounder

The Samsung Galaxy S23 is the direct successor to the size philosophy of the S10e, albeit with a larger screen (6.1 inches). It is a polished, premium device.

The Snapdragon 8 Gen 2 Advantage

For the global market, Samsung switched to the Snapdragon 8 Gen 2, which unified the hardware platform. This is a massive win for developers, as the performance consistency is excellent.

The Custom ROM Hurdle: Knox and RMM

While the S23 is hardware-capable, it is software-restricted.

• Knox Warranty Bit: Unlocking the bootloader on a Samsung device permanently trips the Knox e-fuse. This disables Samsung Pay, Secure Folder, and often Samsung Health forever. It cannot be undone.
• RMM/PIT Locks: Samsung implements strict protection mechanisms (RMM or RIP) that can relock the bootloader if you flash the wrong firmware or factory reset, potentially bricking the device if you aren’t careful.
• Driver Support: Samsung’s drivers are closed-source, making it difficult for developers to get features like the camera performing at stock levels on custom ROMs.

We only recommend the S23 for custom ROMs if you are an advanced user willing to sacrifice Samsung’s proprietary features for the sake of a cleaner OS.

The Underdogs: Sony Xperia 5 Series and ASUS Zenfone

We must also consider devices that often fly under the radar but fit your criteria perfectly.

Sony Xperia 5 V

Sony is one of the few manufacturers that maintains a bootloader unlock portal directly on their website without artificial waiting periods.

• Compact Form: The Xperia 5 V is tall but very narrow, making it highly one-handable.
• Developer Friendly: Sony provides Open Device kits, making it easier to build AOSP-based ROMs.
• Drawback: The community is smaller than Xiaomi or Samsung, so you may find fewer “feature-rich” custom ROMs and more “vanilla” AOSP builds.

ASUS Zenfone 10

The Zenfone 10 was marketed as the last true compact flagship.

• Performance: It has the Snapdragon 8 Gen 2 and a fantastic 5.9-inch screen.
• Unlocking: ASUS allows bootloader unlocking officially, but it often wipes the data and requires an OTA update to a specific firmware version to work correctly.
• Support: The custom ROM scene exists but is less active than the Pixel or Xiaomi scenes. However, for stock software lovers who want the option to tinker, it is excellent.

Deep Dive: ROM Availability and Stability

When we evaluate these phones for you, we look at the stability of the ROMs available on repositories like ours at Magisk Module Repository.

Pixel Experience vs. LineageOS

For the Pixel 7/8, we recommend LineageOS for the most stable daily driver experience. It receives weekly updates and has minimal bugs. Pixel Experience offers the “Google look” but can sometimes be behind on security patches.

MIUI.eu vs. AOSP on Xiaomi

For the Xiaomi 13, the xiaomi.eu ROM is arguably the best version of MIUI. It strips out region restrictions and ads, resulting in a smoother, faster experience than the stock global ROM. If you prefer a Pixel-like experience on Xiaomi hardware, look for Project Elixir or Evolution X, both of which are known for excellent battery optimization.

The “GSI” Option (Generic System Image)

If official support for a phone dies, we often turn to GSIs. These are unmodified Android builds that run on phones supporting Project Treble.

• Samsung S23: Has excellent GSI support due to the Snapdragon chip.
• Sony Xperia 5 V: Also has strong GSI support. This makes the S23 and Sony safer long-term bets, as even when developer interest wanes, you can often flash a generic Android 15/16 GSI to keep the phone alive.

Performance and Thermal Management

A small phone means less surface area for heat dissipation. This is critical when flashing custom ROMs, as aggressive kernels can cause throttling.

• Samsung S23: Has the best vapor chamber cooling in a small phone. It sustains performance longer during gaming or heavy flashing operations.
• Xiaomi 13: Also has excellent cooling, but the smaller chassis can get warm to the touch faster than the S23.
• Pixel 7/8: Tensor chips are notorious for running warmer than Snapdragon counterparts. While manageable, heavy custom ROM tweaking on a Pixel requires careful thermal management to preserve battery health.

The Verdict: Which Phone Should You Buy?

Based on your need to replace a dying S10e with a custom ROM-capable small phone, we have synthesized the data into a definitive recommendation.

1. The “Set it and Forget it” Choice: Google Pixel 8

If you want the path of least resistance and the assurance of long-term updates, choose the Pixel 8. It is the easiest to unlock, has the most stable ROMs, and its compact size is a joy to use. It is the spiritual successor to the enthusiast-friendly Nexus line.

2. The “Power User” Choice: Xiaomi 13 or 14

If you refuse to compromise on hardware—you want that telephoto zoom, the blazing 67W charging, and the raw speed of the Snapdragon 8 Gen 2—the Xiaomi 13 is your machine. You will have to wait for unlock permissions and deal with a more complex ecosystem, but the hardware reward is worth the effort.

3. The “Familiar” Choice: Samsung Galaxy S23

If you are coming from the Samsung ecosystem and simply want a cleaner version of One UI or a near-stock Android experience, the S23 is a safe, premium choice. Just be prepared to see the “Knox Warranty Bit: 0x1” warning forever.

Final Checklist Before You Buy

Before pulling the trigger on any device, we advise running this checklist:

1. Check XDA Forums: Visit the XDA Developers forum for the specific model number (e.g., “Pixel 8” vs “Pixel 8 Pro”). Look for the “ROMs, Kernels, and Recovery” subforum.
2. Verify Unlocking: Search specifically for “Unlock Bootloader [Phone Name]” to ensure the carrier variant you are buying isn’t locked.
3. Check Magisk Support: Since you are visiting Magisk Modules, ensure the device has a working root method. Most Snapdragon devices (excluding US models) and all Pixel devices do.

The era of the small custom ROM phone is fragile, but not dead. With the Xiaomi 13 and Pixel 8, we have two distinct paths: one for hardware maximalists and one for software purists. Choose the path that aligns with your tinkering style, and breathe new life into your mobile experience.