HDRMerge

HDRMerge is a free utility for photographers who bracket exposures in raw format and want the merged file to remain inside a conventional raw-development workflow. It is best for users comfortable with a separate tone-mapping application and with source files from the same camera.

Overview

The software combines exposure-bracketed raw files, including multiple bracketed frames contained in one raw file, into a DNG 1.4 image with floating-point data. By selecting less noisy pixels from the source exposures, the merge is designed to retain shadow information that a single exposure may lose. The resulting DNG is a working raw asset rather than a finished HDR picture: tone mapping takes place later in a compatible editor.

That focused approach is valuable when you want HDR merging to feed RawTherapee, darktable, or recent Adobe software. It is the wrong choice for an all-in-one HDR finishing tool, and it cannot freely mix arbitrary source files. Inputs need matching dimensions, orientation, Bayer pattern, and black and white levels, which in practice generally means files made by the same camera.

Key features

Ghost control

The graphical interface exposes the merge mask for editing. When people or other objects move between bracketed exposures, you can mark which source pixels should contribute and reduce ghosting.

Alignment, cropping, and batch jobs

HDRMerge aligns small translations between source images and crops the result to their shared area, handling the minor framing shifts common in bracket sequences. Its command-line interface can process batches of raw image sets, making it a stronger fit for repeatable or high-volume workflows than a GUI-only application.

Raw-centered output

The floating-point DNG 1.4 output keeps HDR data available for later adjustment in software that understands high-dynamic-range raw DNGs. Because HDRMerge stops at merging, users seeking immediate tone-mapped JPEGs or a complete creative finishing environment should look elsewhere.

Pricing

HDRMerge is free software under the GNU General Public License version 3 or any later version. The Free plan costs nothing, has no trial period because the software is already free, and carries no seat, quota, or renewal terms. Its value is strongest for photographers who can supply compatible raw files and already own or use a separate raw developer; the trade-off is that there is no paid tier offering broader input compatibility or integrated tone mapping.

Platforms

HDRMerge runs on Windows, macOS, and Linux. It supports raw files and produces DNG 1.4 HDR output on each supported desktop platform. Support requests and bug reports are handled through GitHub, with the maker asking for the HDRMerge version, complete error messages, and sample raw-file links when reporting a problem.

Who it's for

Choose HDRMerge if you shoot exposure brackets with a consistent camera setup, want to preserve a raw-style editing path, and value the option to correct ghosts before development. The command line also suits photographers or studios processing many similarly structured sets.

Look elsewhere if your bracket contains files from different cameras or incompatible settings, if you need built-in tone mapping, or if you prefer a single application that merges and finishes HDR images. The matching requirements and separate-development step are central workflow constraints, not edge cases.

Pros and cons

Pros

• Floating-point DNG 1.4 output: keeps merged HDR data in a raw-oriented format for supported developers.
• Editable merge mask: gives you a practical way to reduce ghosts from moving subjects.
• Small-shift alignment and shared-area cropping: handles modest framing differences without requiring separate alignment software.
• Command-line batching: makes repeated raw-set processing more efficient.
• Free GPL license: removes subscription and renewal costs.

Cons

• Strict source matching: size, orientation, Bayer pattern, and black and white levels must agree, limiting mixed-camera workflows.
• No tone mapping: a second application is required to finish the HDR image.
• Manual ghost work: moving-object corrections depend on editing the mask rather than a fully automatic solution.
• Desktop-only reach: there are no Android or iOS versions.

Alternatives

Browse HDR Software for the wider category. ColorForge is a free, no-account, no-watermark option available on Android, iOS, Linux, macOS, the web, and Windows, so it is a better pick for broad device coverage and installation-free use. Instant Meshes is also free on Linux, macOS, and Windows, with no stated price or usage limits.

Luminance HDR is free and open source under GPLv2 for desktop HDR imaging on Linux, macOS, and Windows. Choose PhotomatixCL when a paid, credit-based workflow fits: its Lite plan is $19 a month with 1,000 monthly credits on one system, while Growth is $29 a month. SNS-HDR is a freemium alternative for macOS and Windows with a 30.00 EUR-per-month Home plan.

MergeHDR targets iOS and macOS; its free tier allows previewing and the first 10 exports, up to five per day, while paid plans remove those limits. easyHDR offers Windows and macOS single-user lifetime licenses for home or commercial use at custom pricing. HDR Merge Master is another free desktop option for Linux, macOS, and Windows.

Verdict

HDRMerge is a strong choice for photographers who need a free, raw-first HDR merge with mask editing, modest alignment, and batch processing. Choose it for a disciplined same-camera workflow and downstream raw development; look elsewhere if you need broad input compatibility, built-in tone mapping, or mobile access.