A modernized wrapper around FFmpeg and AviSynth made for converting, cutting, and optimizing videos to WebM and MP4 without dealing with the command line. Fork of argorar/WebMConverter and nixx/WebMConverter.
- Download the latest release here.
- 🚀 Migrated to .NET 8.0 (Windows): Upgraded from legacy .NET Framework 4.8 for better performance, stability, and full compatibility with modern Windows 10/11.
- ⚡ NVIDIA GPU Acceleration (NVENC): Full hardware acceleration for H.264 (
h264_nvenc) and HEVC/H.265 (hevc_nvenc) encoding. Blazing-fast renders using your NVIDIA graphics card. - 🎯 Smart 10 MB & 20 MB Target Size Presets (Discord & Messaging):
- Instant one-click
[ 10 MB ]and[ 20 MB ]buttons right in the encoding settings. - No more cut-off video ends: Eliminated the harsh
-fsbyte truncation cutoff. Replaced with an intelligent 4.5% safety bitrate budget and FFmpeg VBV buffer limits (-maxrate:v,-bufsize:v). Your videos play completely from start to finish without getting cut in the last seconds.
- Instant one-click
- ⏩ Web FastStart (
-movflags +faststart): Automatically places the MP4moovatom at the beginning of the file so exported videos stream and play instantly on Discord, Telegram, Twitter/X, and web browsers without downloading the entire file first. - 📺 YouTube Downloader (HTTP 403 Forbidden Fix & In-App Updater):
- Upgraded built-in
yt-dlpto modern builds (v2026.08.19+). - Integrated anti-bot extractor bypass (
--extractor-args "youtube:player_client=android,web") to prevent YouTube HTTP 403 blocks. - Added an Update yt-dlp button directly in the Settings / General tab for easy one-click updates.
- Upgraded built-in
- 🪟 Resizable UI Window: Main window is now freely resizable (
Sizable) with an expanded default layout (1550px) designed for modern high-resolution displays. - 🔇 Clean FFmpeg Encoding Logs: Passes
-nostdinto FFmpeg, preventing interactive console prompts (Enter command...) andParse errorspam from cluttering the log output. - ⚙️ Optimized Defaults: Pre-configured out of the box with MP4 export, Audio enabled, OnlyFFmpeg enabled, and NVIDIA NVENC selected.
Important to know:
- Requires .NET 8.0 Desktop Runtime (Windows)
- Optional: AviSynth (2.6.0, 32-bit) for advanced AviSynth filters (or use Only FFmpeg mode to encode without AviSynth installed!)
- Already includes a compatible static build of FFmpeg and yt-dlp
- Only works on Windows
WebM is an open, royalty-free, media file format designed for the web. WebM defines the file container structure, video and audio formats. WebM files consist of video streams compressed with the VP8 or VP9 video codecs and audio streams compressed with the Vorbis or Opus audio codecs. The WebM file structure is based on the Matroska container.
For more information about WebM, see the FAQ.
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Openness and innovation. A key factor in the web's success is that its core technologies such as HTML, HTTP, and TCP/IP are open for anyone to implement and improve. With video being core to the web experience, a high-quality, open video format choice is needed. WebM is 100% free, and open-sourced under a BSD-style license.
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Optimized for the web. Serving video on the web is different from traditional broadcast and offline mediums. Existing video formats were designed to serve the needs of these mediums and do it very well. WebM is focused on addressing the unique needs of serving video on the web.
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Low computational footprint to enable playback on any device, including low-power netbooks, handhelds, tablets, etc
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Simple container format
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Highest quality real-time video delivery
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Click and encode. Minimal codec profiles and sub-options. When possible, let the encoder make the tough choices.
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Get the last update with just one click.
You can get and edit your video easly with the next options.
Paste the url of the video you want and press enter, the download will start. You will get the best quality.
- Support for +1000 sites
- You can choose the default path for all your new videos
- Load the new video in the app with just one click
Disable option in general tab to select manually the format do you want.
To download just a part from a youtube video add @*start-end e.g.
https://www.youtube.com/watch?v=_gbUT3AOg@*5:35-5:45
Trim precisely the length, with a simple interface. You can do multiple trims if you need. Go to.. the exact frame or time you want to start the trim, also save the current frame to source path.
Click over trim timestamp start or end, preview will jump to the specific frame.
Crop what is just important for you, you can see in real time the new resolution also you can set the exact size that you want or set an aspect ratio like 16:9, 9:16 and more under Set dimensions. Just move the edges with the mouse or use the keyboard.
Row keysto moveShift + Row keysto move fasterAlt + Row Keysto increase/decrease the sizeCtrl + Row Keysto resize keeping aspect ratio- You can use mouse wheel over time line to change of frame
Follow an object on the canvas easly. Steps for a correct workflow:
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Use trim to define the clip lenght (optional)
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Open Crop filter and select
Dynamic Crop. When it is actived will be green which means that each movement will be registered -
Define the crop size. Even numbers are required
For this example the edition requires 30 seconds.
dynamic-crop-tutorial.mp4
Right side was processed with dynamic crop.
dynamic-crop-result.mp4
Add specific speed to just a section of video:
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Use trim to define the clip lenght
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Dynamic filter will be enable
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Add points in the frame you want with the desire rate (a final ¯\ _ /¯ shape is recomended)
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There is not limit for points
dynamic-rate-turorial.mp4
A specific section is slowdown.
Sting.-.Desert.Rose.Official.Music.Video.mp4
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Make grid videos to compare or shared different views. You can choose between horizontal or vertical. It requires that both videos share codecs, dimensions, length. Output file is in same path as video #1. Above you can find an example.
If your video looks dark, you can try with some pre-set filters. Now you can create your own filter using Advanced option, change gamma, contrast and saturation.
Add text, change font, size, position, also set when it start and end.
Rotate your video to any direction with just one click.
Loop function, forward and reverse making an infinite effect.
AnimatedUnimportantAlligatorsnappingturtle.mp4
Use different levels of stabilization for your clip. Left side original, right side processed. Find it in Advanced>Processing.
DentalAnchoredHedgehog.mp4
Drag and drop two or more video files inside the application, select what do you want to do. Search for the result in source path.
- For merge: The group of videos must have the same encodes / dimensions.
- For convert: The current settings will be apply to all video files
- Export frames
- Add subtitle
- Resize
- Reverse
- Overlay your logo
- Change the speed
- Fade
- Disable audio
- Delay audio
- Get specific filesize in final result
- Get high quality video in webm and mp4 format
- Interpolate, more frames to your video
- Deinterlace
- Denoise
- Trim:
Alt + t - MultiTrim:
Alt + Shift + t - Crop:
Alt + c - Change Rate:
Alt + Shift + c
- Cybelia♡
- Chibi
- bouteloua
- ManletPride
- 3nly
- Clean Encoding Logs: Pass
-nostdinto FFmpeg process arguments to eliminate interactive console prompt spam (Enter command: <target> <time>/Parse error). - YouTube 403 Forbidden Fix: Enhanced yt-dlp arguments with
--extractor-args "youtube:player_client=android,web"and-f "bestvideo*+bestaudio/best"to bypass YouTube bot blocking and stream download errors. - In-App yt-dlp Updater: Added an
Update yt-dlpbutton in General Settings to automatically update yt-dlp to the latest release on demand.
- Discord & Messaging Size Presets: Added
[ 10 MB ]and[ 20 MB ]target size buttons in the Video Encoding tab. - End-of-Video Cutoff Eliminated: Removed the legacy hard
-fsbyte cutoff that abruptly truncated the end of videos. Implemented an automatic 4.5% safety bitrate budget and FFmpeg VBV buffer limits (-maxrate:v,-bufsize:v) so videos finish completely within the file size limit. - FastStart Web Playback: Automatically applies
-movflags +faststartto MP4 exports, moving themoovatom to the file header so videos start playing immediately on Discord, Telegram, and web browsers. - Resizable Window: Main interface is now freely resizable (
Sizable) with a wide default layout (1550px) for modern displays. - Modern Defaults: Default configuration set to MP4, Audio enabled, OnlyFFmpeg enabled, and NVIDIA NVENC selected.
- .NET 8.0 Windows Migration: Migrated entire solution from legacy .NET Framework 4.8 to .NET 8.0.
- NVIDIA NVENC GPU Acceleration: Full hardware-accelerated encoding for H.264 (
h264_nvenc) and HEVC (hevc_nvenc). - Single-Pass GPU VBR/CQ: Fixed
-crfcrash and multi-pass incompatibility when hardware acceleration is active. - Automated CI/CD: Added GitHub Actions build workflow to automatically compile and publish zipped releases.
- Fix generation of output file to detect if exist when load the file issue
- Announcement Original repository frozen by argorar.
- This release is to announce a new software, do you have a mac and want to convert videos in a simple way? Try LazyConverter
- Fix code issues
- Add option to put target frames per second in change rate filter request
- Fix bug loading a second file that makes it stuck at "Extracting subtitle tracks and attachments..." issue
- Fix uncheck loop box after load new video
- Add General button in dynamic crop filter, to add initial and last points with same value
- Add function to load point value in dynamic crop filter if it already exist
- Fix loading files with subtitles
- Fix blocking video source issue
- Add new option to use only ffmpeg, this fix audio synchronization problems and duplicate frames. Check the option in Encoding tab.
- Add support for yuv420p10 with bt.709 issue
- Add merge audio, in track selector choose mix all (only two tracks sopported now) request
- Expand support for HDR
- Fix webms with full range color aren't playing in Chrome issue
- Refactor mp4 codec selector
- Add HDR10 bits support
- Fix darker colors in Chromium browsers
- Fix horizontal and vertical rotation issue
- Fix subtitles with crop
- Fix subtitles issue
- Fix some scenaries to update output filename
- Fix Subtitles get cropped issue
- Fix "Create another" button's suffix malfunctions after 10th file issue
- Now you can set size limit default, find it in General tab request
- Fix for ffmpeg/ffprobe long paths not working by @DoTheSneedful
- Set color range metadata to full levels for a correct color interpretation
- Now you can set default values to caption filter, find it in General tab
- Allow long file names by @DoTheSneedful
- Improve workflow using dynamic filters
- Fix Resize window not showing in second monitor
- Add in caption filter crop zone when it exist previously
- Improve preview performance
- Improve shadow under dynamic points
- Refactor rotate filter to ffmpeg commands
- Update ffmpeg to v6.1
- Add audio amplification option
- Increase cache size for preview frames
- Minor changes underhood and UI
- Add remove option in multi trim. See related request
- Fix target bitrate using constant mode
- Fix size limit using constant mode and change rate filter. See related issue
- Fix yt-dlp.exe v2024.03.10 process. See related issue
- Add option after convert Create another, this will change the output file to -2, -3,.., -n
- Fix filenames when you download many clips from the same file using @* introduced in 3.32.0
Special thanks to original monthly supporters:
- top supporter Chibi ❤︎
To see more changelog.
This software is released under the MIT license.