Pure Mode in FiveM: Server-Side File Integrity Enforcement

With sv_pureLevel 0, no file validation is performed. Players can join with any combination of modified files, including custom textures, replacement models, audio packs, ENB/ReShade presets, and even modified script files. This is the default setting on every FiveM server.

Best for: Development servers, servers that actively encourage client-side modding, or communities where visual customization is part of the culture.

Level 1 — Light Mode

Level 1 takes a selective approach. It permits modifications to files that are primarily cosmetic while blocking file types that can alter gameplay logic:

Allowed:

• .ytd texture files (custom skins, vehicle liveries, UI textures)
• .ydd and .ydr model variations (clothing, vehicle body kits)
• Audio modifications (custom radio stations, engine sounds)

Blocked:

• .ysc script files (game logic modifications)
• .asi injectors (common cheat delivery method)
• Modified executables and DLLs

This level is popular because it lets players keep their visual mods — custom car textures, clothing packs, or even graphical presets that rely on texture replacements — while preventing the file types most commonly associated with cheating.

Best for: Roleplay servers, casual communities, and any server where player self-expression matters but you still want baseline protection against script-based exploits.

Level 2 — Harsh Mode

Level 2 blocks all file modifications that aren't explicitly whitelisted by FiveM itself. This includes graphical enhancement mods, custom radio stations, texture replacements, and model swaps. Only completely vanilla game files pass validation.

Best for: Competitive servers, racing communities, servers with prize pools, or any environment where absolute fairness is more important than visual customization.

How the Connection Process Works

When a player connects to a server running Pure Mode, the following sequence occurs:

1. The client initiates a connection and begins the handshake.
2. The server requests hash values for specific game files based on the active sv_pureLevel.
3. The client computes and sends file hashes.
4. The server compares received hashes against known vanilla values.
5. If all hashes match, the connection proceeds normally.
6. If mismatches are detected, the player receives a "Files have been modified" error and is disconnected.

Players who are rejected must restart FiveM entirely — the client needs a full restart to reload vanilla files from its cache. Simply disconnecting and reconnecting will not work because the modified files remain in memory.

How Pure Mode Affects Player Experience

The impact on players depends heavily on which level you choose.

On Level 1 servers, most players won't notice anything different. The majority of popular FiveM visual mods — car texture packs, custom clothing, and audio replacements — use the file types that Level 1 permits. Players who use script-based mods or .asi loaders will be blocked, but that's generally the intended outcome.

On Level 2 servers, the experience is more restrictive. Players who are accustomed to running ENB presets, ReShade configurations, or any visual modifications will be unable to join without removing them first. This can cause friction, especially in communities that previously allowed visual mods. Clear communication about your Pure Mode policy — ideally in your server listing, Discord, and connection screen — helps reduce support tickets.

Connection time increases slightly with Pure Mode enabled. The hash validation process adds roughly 2-5 seconds to the initial connection. After that, there is no ongoing performance impact during gameplay.

Pure Mode and Other Security Measures

Pure Mode works best as part of a layered security approach. On its own, it handles file integrity but leaves gaps that other tools need to fill:

• Anti-cheat resources like those covered in our best FiveM anticheat scripts guide detect runtime cheats, injection attacks, and suspicious player behavior that Pure Mode cannot see.
• Server-side validation ensures that critical game logic (damage calculations, inventory limits, economy transactions) is authoritative on the server rather than trusting client-reported values.
• Admin tools and logging provide the human oversight layer, letting staff investigate reports and review player activity.

A solid security setup for a competitive server might look like this:

sv_pureLevel 2
# Combine with anti-cheat resource

ensure your-anticheat-resource
ensure admin-logging-system

For roleplay servers that want a less restrictive but still protected environment:

sv_pureLevel 1
# Allow visual customization while blocking exploits

Choosing the Right Level for Your Server

The right Pure Mode level depends on your server's purpose and community expectations.

| Server Type | Recommended Level | Reasoning | |

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