Image Compare Tool — Before & After
Compare two images side by side with slider, overlay, and pixel difference modes to spot changes instantly.
What to do next
About Image Compare Tool
Image Compare Tool performs image compare tool as a focused single-page utility. Compare two images side by side with slider, overlay, and pixel difference modes to spot changes instantly. Defaults are tuned for the common case so the first run is one click, with every option that matters exposed for the moments you need to fine-tune the result.
Image Compare Tool is shaped around the recurring needs of two audiences: students compiling visual reports, who use it as a quick utility between bigger tools, and social-media managers sizing posts, who use it as their primary way of getting the job done. Both groups get the same defaults and the same speed.
The right moment to reach for Image Compare Tool is when you have a focused image editing and conversion job that fits inside a browser tab. Open the page, drop in the file or paste your input, choose the options that matter, and the tool returns the result.
The processing pipeline is straightforward: your input is parsed by standard browser APIs, transformed according to the options you select, and serialised back into a downloadable result. Accepted input formats are PNG, JPG, GIF, WebP, BMP, and SVG. The 100 MB per-file ceiling matches what a typical browser tab can handle without paging to disk.
Because everything runs in the page, the tool scales the same way for one user or a million — there is no per-user backend cost. The page is static, the engine is the same JavaScript bundle for every visitor, and the work happens on the visitor's own device. That keeps the tool free and keeps it fast on the first interaction.
Workflow tip: Image Compare Tool pairs well with Image Metadata Viewer and QR Code Reader. Other adjacent tools you may find useful are Image Filters and Brightness & Contrast Tool. Because every tool is a separate page, you can mix and match the steps that match your job. Bookmark the ones you reach for the most.
On limits: 100 MB per file is the ceiling. Output formats and quality settings are listed in the controls panel above, and they apply to every run.
Image Compare Tool is built around steady iteration on a small set of options rather than feature creep. Every additional setting attracts a slightly different audience, but a long settings panel makes the common case slower for everyone. The current controls reflect what users of the tool actually use.
Once the engine finishes, the output is offered as an immediate download. There is no preview gate, no email-wall, and no "register to download" intermediary — the file is yours the moment it is ready.
From a product perspective, Image Compare Tool is one of the simplest possible expressions of "do one thing well." The catalog contains dozens of related tools that each handle a slightly different image editing and conversion task, and every one is a separate page rather than a tab inside a larger app. That separation keeps each tool fast to load and easy to bookmark.
Image Compare Tool runs as a regular web page, so there is no install step or permission grant before the first run. The page can be audited by viewing the source or by watching the developer-tools Network tab while a job runs.
A few practical tips that experienced users of Image Compare Tool pick up over time. First, keep your default browser updated — the engine relies on standard web APIs and newer browser versions are noticeably faster than ones from a few years ago. Second, close other heavy tabs before processing a large input; the engine shares CPU and memory with whatever else is open. Third, if you re-run the same kind of job often, your last-used settings are remembered for the rest of the tab session, so subsequent runs are essentially one click.
If Image Compare Tool appears to hang, the engine is almost certainly still working — large inputs simply take longer to process inside a browser than they would on a server with multi-core scheduling. For inputs near the 100 MB cap, give it up to a minute on a typical laptop before assuming something is stuck.
That is essentially everything Image Compare Tool does and how it does it. Open the tool above, drop in your input, and the work happens in the page. If you find yourself reaching for it often, bookmark the page — it loads quickly on subsequent visits, and your most-recent settings are remembered for the rest of the session.
How it works
- 1Land on the Image Compare Tool page. The tool is ready to use the moment the page renders.
- 2Drop a PNG, JPG, GIF, WebP, BMP, and SVG file onto the upload area, or click to pick one from your device.
- 3Pick any non-default settings you need. Most users leave the defaults alone for the first run and only revisit if the result needs tuning.
- 4Hit the run button. standard browser APIs does the work in your browser tab.
- 5Grab the output as soon as the run completes. You can also copy the result instead of downloading if the next tool in your workflow accepts pasted input.
- 6Re-run with different settings as often as you want. Each run produces a fresh output and the original file on disk is never modified.
Common use cases
- Convert a batch of camera files into web-friendly formats using Image Compare Tool.
- Convert a phone screenshot into a CMS-friendly format.
- Resize a hero image for a landing page without losing crispness.
- Strip EXIF data from a photo before posting it publicly.
- Optimise a product photo so it loads quickly on a slow connection.
- Compose a mockup banner without bouncing between three different apps.
- Prepare a transparent logo for use over different backgrounds.
- Sharpen a slightly soft photo before sending it to print.
- Produce a printable card from a single source image.
- Generate a square thumbnail from a wide marketing photo.
FAQ
Comparison modes?
Slider (before/after), side by side, pixel difference map, and toggle overlay.
Pixel diff?
Highlights pixel differences in a configurable color — useful for testing visual regression.
Same dimensions?
For best results, both images should have the same dimensions.
Is my data safe?
Everything runs in your browser — nothing is uploaded.
Output?
Canvas API code for the selected comparison mode.
Sensitivity?
The diff threshold can be adjusted to ignore minor color variations.
Are there any usage limits on Image Compare Tool?
Inputs are capped at 100 MB per file, which keeps memory usage stable across phones, tablets and older laptops. You can run Image Compare Tool as often as you need; every run produces a full-quality result.
How accessible is the Image Compare Tool interface?
Image Compare Tool uses native HTML controls wherever possible, which means keyboard navigation, focus rings, and screen-reader labels work the way the platform expects. The drop zone accepts files via the keyboard-accessible file picker as well as drag-and-drop, and result downloads use standard browser download flows. If you spot an accessibility gap, Favtoo treats it as a bug worth fixing.
How long does Favtoo retain my data after using Image Compare Tool?
Favtoo keeps no copy of your file because Favtoo never receives your file. Image Compare Tool runs entirely in your browser, the input is held only in your tab's memory, and closing the tab discards it. There is no opt-in cloud history, no "recent jobs" panel synced to an account, and no server-side retention to configure — the architecture simply has nowhere for your file to be stored.
Can I use Image Compare Tool for commercial work?
Image Compare Tool can be used for personal and commercial work alike — there is no separate "business" licence to purchase. The output you generate is yours to use however you want, including in client deliverables, internal documents, or commercial products. Favtoo's only ask is fair, individual use; the tool is not designed to be embedded as a backend service or wrapped behind an API for resale.
Will I notice a difference in the output from Image Compare Tool?
Image Compare Tool is built to preserve quality wherever the underlying image format allows it. Operations that are mathematically lossless (e.g. structural transformations, lossless re-encoding) round-trip with no perceptible change. Operations that involve a lossy codec inevitably introduce small artefacts at the byte level, but the defaults aim at the sweet spot where output looks or sounds the same to a normal viewer or listener while still being meaningfully smaller or faster than the input.
What does Image Compare Tool do that command-line tools do not?
Desktop apps usually have more advanced features but require installation, maintenance and (often) a licence. Paid online tools are convenient but route your file through their servers and gate downloads behind accounts. Image Compare Tool sits in between: free, instant, and private, but intentionally narrow in scope. For one-off jobs and the common image editing and conversion operations, it is usually the lowest-friction choice; for highly specialised work, a dedicated app is still the right answer.
Why is my browser prompting me when I open Image Compare Tool?
Image Compare Tool only needs the standard web platform — file picker access for the inputs you choose to load, and optionally clipboard access if you copy the result rather than downloading it. There is no microphone, camera, geolocation or background-permission request, because none of those are needed for the work the tool does.