Hammer++

Free plan LinuxWindows

What Hammer++ is

Hammer++ is a free Windows modification of Valve’s Hammer editor for making maps in the Source engine. Its stated purpose is to provide a more stable and current editor through bug fixes and improvements. It simulates Source lighting inside the editor, with configurable quality and speed and dynamic updates. Visual previews include particles, fog, skyboxes, rope physics, render effects, and material proxies. Mapping tools include a 3D gizmo, polygon and sprinkle tools, multiple cordons, brush merging, and object placement on floors or ceilings. If the editor crashes, it displays a detailed error message and autosaves open VMF files. Saved VMFs preserve precise vertex data while also including imprecise data for compilers and compatibility with other Hammer versions. Downloads bundle HLMV++, which users can optionally install. The maker directs users to the official Discord for discussion and says Hammer++ is not affiliated with Valve Corporation. The download page lists build 8871, last updated April 14, 2026. The maker also says antivirus software sometimes flags downloads and advises allowing them or adding an exception.

Who it suits

Hammer++ suits Windows users making maps with the Source engine who want lighting previews, visual previews, and additional mapping tools. It is a modification of Valve’s Hammer editor, not an official Valve product.

What it does well

Simulates Source lighting with configurable quality and speed
Previews particles, fog, skyboxes, and other effects
Autosaves open VMF files after a crash
Includes mapping tools such as brush merging
HLMV++ is bundled and optionally installable

What to know first

Keybind editor cannot assign mouse bindings
Modifier keys may not work for every binding
Old Source 2013 Multiplayer version is unsupported
CS:GO support is frozen on build 8864

Limits

The editor is for Windows. Source 2013 Multiplayer is unsupported, and CS:GO support is frozen on build 8864. The keybind editor cannot assign mouse bindings, and modifier keys may not work for every binding.

Plans

Plan	Billed and limits	Price
Hammer++	Source-engine level editing · branch-specific builds · Windows download	Free

As ficool2.github.io lists them, read 15 Oct 2026. The maker's own page has the final word.

Getting started

Visit the Hammer++ website.
Download Hammer++ for Windows.
Optionally install bundled HLMV++.
Use the official Discord for discussion if needed.
If antivirus flags the download, follow the maker’s advice to allow it or add an exception.

Verdict

Hammer++ adds lighting and visual previews, mapping tools, and crash recovery to a free Windows editor for Source maps. Be aware of its keybind and compatibility limits, and that antivirus software may flag its downloads.

Questions

Does Hammer++ cost anything?

No. Hammer++ is a free modification of Valve’s Hammer editor.

Which operating system does it support?

The listed platform is Windows.

What is included with the download?

The download page says HLMV++ is bundled and can be installed optionally.

Which Source versions are supported?

The page says Source 2013 Multiplayer is unsupported and CS:GO support is frozen on build 8864.

Is Hammer++ affiliated with Valve?

No. The site says Hammer++ is not affiliated with Valve Corporation.

Where can users discuss Hammer++?

The maker directs users to the official Discord.

Facts from Hammer++'s own pages

Antivirus issue: The maker says downloads are sometimes marked as malware by antivirus software and advises allowing them or adding an exception. · ficool2.github.io, 28 Sept 2026
Branch compatibility: Separate downloads exist for different Source branches, and the site warns that choosing the wrong branch prevents startup. · ficool2.github.io, 15 Oct 2026
Bundled companion: HLMV++, a model viewer, is bundled with downloads but is optional to install. · ficool2.github.io, 15 Oct 2026
Compatibility limits: The page says the old Source 2013 Multiplayer version is unsupported and CS:GO support is frozen on build 8864. · ficool2.github.io, 28 Sept 2026
Compile workflow: Compilation runs in a separate command window so the editor no longer freezes during compiling. · ficool2.github.io, 15 Oct 2026
Crash recovery: If Hammer++ crashes, it displays a detailed error message and autosaves open VMF files. · ficool2.github.io, 28 Sept 2026
Current build: The download page lists build 8872, last updated October 1, 2026. · ficool2.github.io, 15 Oct 2026
Download status: The download page lists build 8871, last updated April 14, 2026. · ficool2.github.io, 28 Sept 2026
Editing tools: It adds a 3D gizmo, adjustable pivot, polygon and sprinkle tools, real-time vertex editing, three-point clipping, brush merging and surface movement tools. · ficool2.github.io, 15 Oct 2026
File compatibility: Hammer++ saves precise vertex data in VMF files while also saving imprecise data for compilers and compatibility with other Hammer versions. · ficool2.github.io, 28 Sept 2026
GPU requirements: VRAD++ GPU acceleration requires at least an Nvidia RTX 2000-series, AMD RX 6000-series or Radeon 680M+, or Intel Arc A-series GPU with Vulkan 1.3 drivers. · ficool2.github.io, 15 Oct 2026
Independent complaint: camera controls: A Mapcore reviewer reported that arrow keys could not rotate the 3D camera as in vanilla Hammer. · mapcore.org, 15 Oct 2026
Independent complaint: missing asset filters: A Mapcore reviewer missed a used-assets-only filter and model usage counts in the model browser. · mapcore.org, 15 Oct 2026
Independent complaint: texture scaling: A Mapcore user found that stretching brushes also stretched their textures, requiring frequent face-edit adjustments until texture lock was discovered. · mapcore.org, 15 Oct 2026
Independent Linux experience: A Reddit Linux guide reports Hammer++ can run through Proton, with working lighting, compilation, custom assets, logic and 3D view, but buggy and laggy 2D and texture-browser interfaces. · reddit.com, 15 Oct 2026
Independent popularity claim: A Steam Community overview described Hammer++ as making Source level creation significantly faster and demonstrated model, skybox, particle, fog, rope, gizmo and lighting features. · steamcommunity.com, 15 Oct 2026
Independent praise: lighting: Mapcore users repeatedly praised the lighting preview as useful for making lighting changes without compiling and liked the skybox preview. · mapcore.org, 15 Oct 2026
Independent praise: modern manipulation: Mapcore reviewers highlighted the 3D gizmo for translating, rotating and resizing objects and welcomed the broader quality-of-life improvements. · mapcore.org, 15 Oct 2026
Independent product description: BSPMarket describes Hammer++ as a free ficool2-developed Valve Hammer extension with separate builds for Garry’s Mod, Team Fortress 2 and Portal 2. · bspmarket.de, 15 Oct 2026
Independent setup guidance: Momentum Mod documentation recommends the Garry’s Mod build as easier to configure and says the CS:GO setup needs more tools and disk space. · docs.momentum-mod.org, 15 Oct 2026
Independent setup limit: Momentum Mod’s CS:GO setup guide estimates about 32 GB of disk space depending on mounted games. · docs.momentum-mod.org, 15 Oct 2026
Installation: Installation instructions are supplied in README.txt inside each download, and updates are installed by overwriting the existing files. · ficool2.github.io, 15 Oct 2026
Integrations: The download page says HLMV++ is bundled with downloads and can be optionally installed. · ficool2.github.io, 28 Sept 2026
Keybinding limitation: The keybind editor cannot assign mouse bindings, and modifier keys may not work for every binding. · ficool2.github.io, 15 Oct 2026

Where Hammer++ stands on Freedom251

Game Level Editors#10 of 28