SpectralBench
View any spectroscopy file directly in your browser
Research labs, teaching environments, and QA teams regularly deal with spectral data files locked inside proprietary formats. Without the right vendor software — which is often expensive and platform-specific — simply viewing a spectrum can be a roadblock. SpectralBench removes that barrier with a free online spectrum viewer that runs entirely in your browser.
Drag any JCAMP-DX, SPC, Bruker OPUS, or CSV file into SpectralBench and get an interactive chart in seconds. SpectralBench parses the file on your machine — nothing is ever uploaded to a server — so your data stays private. Whether you need to quickly inspect an FTIR absorption spectrum, view JCAMP-DX files online, explore the metadata embedded in a legacy SPC file, or open spectra from the reference library for comparison, the viewer gives you the tools you need without the overhead.
Getting started takes seconds: drag and drop any spectral file onto the viewer, or click the upload area to browse your files. SpectralBench automatically detects the file format — whether it is JCAMP-DX, SPC, Bruker OPUS, CSV, or plain text — and parses it entirely client-side. No plugins, no downloads, no server round-trips.
Once parsed, an interactive chart renders your spectrum with wavenumber or wavelength on the x-axis and absorbance or transmittance on the y-axis. Use the crosshair tool to read exact values at any point, zoom into regions of interest with click-and-drag, or toggle the peak detection overlay to automatically label absorption bands and valleys.
For deeper inspection, switch to the annotated view to see the raw file source with inline documentation explaining every header field, data block, and metadata tag. This is especially valuable when troubleshooting file compatibility issues or verifying that instrument parameters were recorded correctly. When you are ready to share or reprocess your data, use the Spectral File Converter to export to CSV for further analysis in Excel or Origin.
SpectralBench now supports loading multiple spectra simultaneously for direct visual comparison. Each spectrum is automatically assigned a distinct color, and an interactive legend lets you toggle individual traces on and off. Use offset or stack modes to separate overlapping spectra vertically, making it easy to spot differences between samples.
Beyond visualization, you can perform mathematical operations on loaded spectra: subtract one from another (A-B) to isolate differences, average multiple scans to improve signal-to-noise, or compute ratios for quantitative comparison. When you are ready to publish, export your chart as an SVG image with journal-specific formatting presets for Nature, ACS, RSC, and Elsevier. For more advanced comparison workflows, use the Compare Spectra tool with its five dedicated visualization modes and HQI similarity scoring.
JCAMP-DX (.jdx, .dx) — The IUPAC/JCAMP standard for spectroscopic data exchange. Widely used in academic research and open-access spectral databases, JCAMP-DX is text-based and self-describing. Despite being an open standard, many tools do not support its full specification, including compressed data formats and multi-block files. SpectralBench handles the complete JCAMP-DX specification so you can view JCAMP-DX files online without worrying about compatibility. For a deeper dive into format differences, see our guide to spectral file formats.
SPC (.spc) — The Thermo/Galactic GRAMS binary format, common in analytical labs running Thermo Fisher instruments. SPC files store single or multiple spectra with rich metadata, but opening them typically requires GRAMS or compatible commercial software. SpectralBench reads the full SPC binary structure including old and new format variants — a free alternative to open SPC spectral files in your browser.
Thermo Fisher SPA (.spa, .spg) — The native FTIR format produced by Thermo's OMNIC and OMNIC Paradigm software, used across the Nicolet instrument line. SpectralBench parses the OMNIC binary structure — title, key directory, and float32 data block — entirely client-side, so you can open SPA files without OMNIC or a Thermo hardware license. SPG group files load their first spectrum.
Bruker OPUS (.0, .1, .2, ...) — The proprietary binary format from Bruker FTIR spectrometers. Numbered file extensions make OPUS files unrecognizable to most operating systems and software. Viewing them usually requires Bruker's OPUS software, which is expensive and Windows-only. SpectralBench lets you view Bruker OPUS files online from any platform at no cost.
CSV / TXT — Universal tabular formats that are easy to work with but lack embedded metadata. SpectralBench auto-detects the delimiter and column layout, so you can view spectral data exported from virtually any instrument or software package. For more structured output, use the converter to produce a JCAMP-DX file with proper metadata.
Need help opening files from a specific instrument? See our vendor-specific guides:
Drag and drop your .jdx or .dx file onto SpectralBench. The viewer parses JCAMP-DX files entirely in your browser — no software to install, no account to create. Your spectrum renders as an interactive chart within seconds.
Yes. SpectralBench parses Bruker OPUS binary files directly in the browser. You do not need Bruker's OPUS software or a Windows machine. Simply drop your .0, .1, or .2 file onto the viewer to see your spectrum instantly.
No. SpectralBench processes every file 100% client-side using JavaScript in your browser. Your data never leaves your machine and is never transmitted over the network.
The viewer works with any technique that produces x-y spectral data, including FTIR, Raman, UV-Vis, NIR, and SERS. As long as your data is in a supported format (JCAMP-DX, SPC, Thermo SPA, OPUS, CSV, or TXT), SpectralBench can display it.
Yes. After loading a spectrum you can export your data to CSV, JCAMP-DX, or JSON using the built-in converter. This makes it easy to share data with colleagues who use different software or to import into tools like Excel, Origin, or MATLAB.
Yes. Load multiple spectral files and SpectralBench displays them simultaneously with color-coded traces and an interactive legend. Use offset or stack display modes to separate overlapping datasets for clearer visual comparison.
Yes. SpectralBench exports publication-ready SVG images with journal-specific formatting presets for Nature, ACS, RSC, and Elsevier. Customize axis labels, line widths, and colors to match your target journal's requirements.
Compare spectra with overlay, difference, and similarity scoring modes.
Convert your spectral files to other formats like CSV or JCAMP-DX.
Upload your FTIR spectrum and identify functional groups automatically.
Baseline correction, smoothing, and normalization for your spectra.