Video Grayscale performs video grayscale as a focused single-page utility. Choose Rec. 709 luma weights, average RGB, or custom coefficients for monochrome conversion with optional dithering. 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.
If you fit any of these descriptions, Video Grayscale should slot cleanly into your workflow: event organisers sharing highlight footage; creators trimming short clips; product teams shipping release demos. The tool keeps the controls focused on what matters for each of these use cases.
The execution path is auditable from the page itself: open developer tools, switch to the Network tab, run a job. The requests you see are static-asset GETs for the engine and the page resources. The actual work is JavaScript code running against the bytes already in your tab's memory.
Behind the controls you see, FFmpeg compiled to WebAssembly is doing the actual video editing and conversion. MP4, WebM, MOV, MKV, AVI, FLV, and OGV are first-class formats and the engine produces a deterministic output for any given input + options combination — useful when you need to re-run a job and expect identical results.
The right moment to reach for Video Grayscale is when you have a focused video 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.
Workflow tip: Video Grayscale pairs well with Video Brightness & Contrast and Video Saturation. Other adjacent tools you may find useful are Video Fade and Video Blur. 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.
The output handed back by Video Grayscale is `{name}-edited.{ext}`. If you would prefer to keep the result in the browser instead of downloading it, you can copy it from the result panel and paste it directly into another tab — useful when the next tool in your workflow expects pasted text rather than a file.
The only practical limit is the 500 MB per-file ceiling, which keeps the tool responsive across a wide range of devices. Run the tool ten times in a row, run it ten thousand times — it behaves the same way and produces the same quality of result.
Video Grayscale is honest about scope: it handles a single, well-defined video editing and conversion step. Specialist edge-case work — uncommon formats, very large inputs, or pipelines that need scripting — is what dedicated desktop apps are for. This page handles the common case quickly.
A short note on how Video Grayscale came to look the way it does: every iteration started by watching how someone unfamiliar with the tool actually used it, then removing whatever got in their way. That is why the upload area dominates the screen, the run button is bigger than the secondary controls, and the result panel is unmissable when the job finishes.
Useful patterns when working with Video Grayscale: keep the input file open in another tab so you can compare against the result; give the output file a descriptive name when saving so you can find it later (the default name is sensible but generic); and treat each run as independent — the tool has no concept of "history", which means you cannot accidentally pollute one job with leftovers from another.
When something goes wrong, the cause is usually one of three things: a malformed input, a browser that is out of memory, or a corporate proxy that is interfering with the page's static assets. The first two are easy to diagnose; the third typically requires asking your IT team to allow FFmpeg compiled to WebAssembly to load.
If you also use a command-line tool for video grayscale, Video Grayscale is a convenient alternative for the times you are on a different machine or helping someone who is not comfortable in a terminal. The output is a standard file in the format documented above.
Open the workspace above to start using Video Grayscale. The engine loads on the first interaction so the page itself stays light, and once the tool is warm it processes subsequent jobs quickly. The moment the page is interactive, the tool is ready to do real work on your file.
The hue filter is applied with saturation set to 0, which uses the standard Rec. 709 luma weights to convert to monochrome — the same conversion every modern broadcast uses, matching human brightness perception.
Yes — audio is kept untouched and re-encoded to AAC alongside the grayscale video.
MP4 with H.264 video and AAC audio. Works in every modern player and on all social platforms.
Slightly — chroma information compresses better when it's constant, so expect a 5–15% smaller file at the same CRF compared to the colour original.
Cloud tools run on dedicated server CPUs but require uploading your file. This tool runs FFmpeg as WebAssembly inside your browser, so processing speed depends on your own hardware. Smaller resolutions and shorter clips finish faster.
Completely. Your file never leaves your device — no upload, no account, no watermark.
Up to 500MB. Larger files may exhaust the browser tab's WebAssembly memory.
Video Grayscale accepts MP4, WebM, MOV, MKV, AVI, FLV, and OGV. If your input is in a format that is not directly supported, convert it first using one of Favtoo's converter tools — every Favtoo converter outputs a file that is a clean input to the next tool in the chain.
Video Grayscale processes one input at a time by design — it keeps memory usage predictable on lower-end devices and makes results easier to verify. To handle a folder, run the tool once per file; the page stays loaded between runs and remembers your last-used settings, so the second run is essentially instant.
Failures usually fall into one of three buckets: the input is in an unsupported format, the input is over the size cap, or the input is structurally malformed (a truncated download, a partial export, or a stream the engine does not recognise). The first two are easy to confirm — check that your file is one of MP4, WebM, MOV, MKV, AVI, FLV, and OGV and that it is below 500 MB. For the third, opening the file in its native viewer first is the fastest way to confirm the source is intact.
Once the page is loaded, Video Grayscale can complete jobs without an active internet connection — the engine is bundled with the page, so there is no per-job network call. The initial page load does require a connection (to fetch the static assets), but after that you can disconnect entirely and the tool will still work. This is a side-effect of the local-first architecture, not a deliberate "offline mode" feature.
Video Grayscale runs in any modern mobile browser — Safari, Chrome, Firefox and the in-app browsers in most messaging apps all support the underlying APIs. Performance depends on the device: a recent phone handles typical inputs nearly as fast as a laptop, while older devices may take a few seconds longer near the 500 MB ceiling. The interface lays out cleanly on small screens, so you do not need to pinch-zoom to see the controls.
Most jobs finish in seconds. Speed scales with input size and with how many CPU cycles your browser tab has available — the engine runs in your browser, so it shares resources with whatever else you have open. For inputs near the 500 MB ceiling, expect anywhere from a few seconds to roughly a minute on a typical laptop. Closing other heavy tabs noticeably speeds things up.
Video Grayscale is a static page running an open-source engine in your browser, so a typical corporate firewall does not get in the way as long as it allows JavaScript and WebAssembly to load from Favtoo. For teams that need to host it themselves on an internal network, the underlying engine (FFmpeg compiled to WebAssembly) is open-source and can be packaged into a private build with the same behaviour. Reach out via the Contact page if that is something you are exploring.
Video Grayscale is a browser-only tool by design and does not expose a hosted API. The reason is the same as the privacy story: there is no Favtoo backend doing the work, so there is no service to call. If you need to script the same transformation, the underlying engine (FFmpeg compiled to WebAssembly) is open-source and can be used directly from your own code.
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. Video Grayscale sits in between: free, instant, and private, but intentionally narrow in scope. For one-off jobs and the common video editing and conversion operations, it is usually the lowest-friction choice; for highly specialised work, a dedicated app is still the right answer.
Video to GIF
Convert any video clip to an animated GIF entirely in your browser. Pick the start, length, frame rate, and width — your file is processed locally with FFmpeg WebAssembly and never uploaded.
Screen Recorder
Record your screen, a window, or a browser tab directly in your browser. Optionally include system audio and your microphone. Capture, preview, and download the video without installing any app — and without uploading anything.
Webcam Recorder
Record your webcam directly in your browser with optional microphone audio. Pick the resolution (480p, 720p, or 1080p), frame rate, and mirror mode, then capture and download the result without installing any app.
Screen + Webcam Recorder
Record your screen with your webcam composited into a picture-in-picture corner — perfect for tutorials, course videos, demos, and reaction recordings. Pick the camera position, size, and audio sources, then capture and download in your browser.
Video Slideshow Maker
Turn a stack of photos into an MP4 slideshow with per-slide durations, crossfades, and an optional soundtrack. Pick the resolution (up to 1080p), frame rate, and transitions, then download a single MP4 — all processed in your browser with FFmpeg WebAssembly.
Video from Images + Audio
Combine a stack of photos with a music track or narration into a single MP4 video. Pick the resolution, per-slide duration, transitions, and let the slideshow length match the audio. All processed in your browser with FFmpeg WebAssembly.
Video Trimmer
Set precise in and out timestamps, snap to keyframes when needed, and document handles for social-safe cutdowns.
Video Splitter
Split any video into 2–10 equal-length pieces, packaged as a downloadable ZIP. Files are processed entirely in your browser with FFmpeg WebAssembly using lossless stream-copy.