What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
You may not need to convert WebM files for OBS: OBS lists both WebM and MP4 as supported media types. First test your files in the playlist source and setup you plan to use. Convert only if a file fails to play or your target requires MP4. For playlists, OBS documents the VLC Video source, which requires VLC to be installed.
Do you need to convert WebM to MP4?
Not just because the files end in .webm. OBS’s Media Sources guide lists both WebM and MP4 as supported video types. That does not guarantee every codec, system, or software build will play every file, so test representative clips in the actual OBS scene and computer you will use.
OBS describes MP4 as the de facto standard for internet video in its Audio/Video Formats Guide. The useful question is whether your target can play the file—not whether MP4 is inherently better or whether changing the extension will fix it.
Set up and test a playlist in OBS
- Install VLC. In OBS, add a VLC Video source for the playlist. OBS’s guide says VLC must be installed for this source to appear; with 64-bit OBS, use 64-bit VLC.
- Add a representative WebM file to the source and check both picture and sound in the scene you intend to stream.
- If it plays correctly, keep the original file. Use the source’s loop and shuffle controls to choose the playlist behavior. OBS documents loop as on and shuffle as off by default.
- Test transitions between files before relying on the playlist during a live stream. If only some files fail, handle those files individually rather than converting the whole collection automatically.
See the OBS Media Sources guide for the source’s current controls. Its page is dated 2022-01-11, and software support can change.
Recommended Free Tools
#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
Choose streamcopy or transcoding
If a file does not play and MP4 is needed, inspect its video and audio streams, then choose between streamcopy and transcoding. FFmpeg’s documentation distinguishes the two approaches:
- Streamcopy copies encoded streams into a new container without decoding or re-encoding them. It is fast and avoids encoding quality loss when the streams can be muxed into the destination container. It can fail if the source streams are unsuitable for MP4, and the receiving software still needs to decode their codecs.
- Transcoding decodes and re-encodes streams into codecs the target can handle. It takes computation, and re-encoding often degrades quality. Choose codecs and quality settings for the actual target and source; there is no universal preset guaranteed to suit every file.
FFmpeg documentation is regenerated as the project evolves, and available encoders depend on your local FFmpeg build.
Rank #2
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
Convert a WebM file with FFmpeg
Try streamcopy when the streams are compatible
Use a new output filename so you preserve the original:
ffmpeg -i input.webm -c copy output.mp4This attempts to copy the streams without re-encoding. If FFmpeg reports that a stream cannot be muxed into MP4, or the resulting file does not play in the target, use transcoding instead. A successful container change does not make an unsupported codec playable.
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
Transcode when the target cannot decode the original codec
FFmpeg documents this general conversion pattern:
ffmpeg -i input.webm output.mp4When you do not specify codecs, FFmpeg uses the output muxer’s default encoder for each stream type; which encoders are available depends on your build. This command is a starting pattern, not a guarantee of a particular quality level or compatibility. If you need specific codecs or quality settings, select them based on the source streams and the target’s documented requirements.
Validate the converted file before using it
- Open the output MP4 in the same OBS VLC Video source and scene you will use for streaming.
- Check the entire clip, including its audio, duration, and ending.
- Test the playlist transition to the next item and confirm the intended loop or shuffle behavior.
- If playback still fails, check which stream or codec the target cannot handle and whether VLC, OBS, and FFmpeg are the intended builds for your system. Revisit the conversion choice rather than renaming the file extension.
Common problems and fixes
- VLC Video is missing from the OBS source list: install VLC, then check that its architecture matches OBS. The OBS guide calls for 64-bit VLC with 64-bit OBS.
- The WebM file appears in a playlist but has no picture or sound: test it in the intended scene, then check its streams and codec compatibility. WebM support does not establish compatibility for every file and build.
- Streamcopy fails: the source streams may not suit the MP4 container. Try transcoding to codecs supported by the target.
- The MP4 exists but still will not play: changing containers alone does not change the codecs when using streamcopy. Check whether the receiving software can decode them; transcode if it cannot.
- The converted clip plays but the playlist behaves unexpectedly: test loop, shuffle, and transitions in the VLC Video source before streaming. The documented defaults are loop on and shuffle off.
Or let it run in the cloud
If your goal is to keep a YouTube channel live with uploaded videos, StreamNeo is a cloud option rather than an OBS playlist workflow: upload your recording or build a playlist, add your YouTube stream key, and go live. Nothing has to stay on at home; it streams uploaded files at their original quality up to 4K 60fps for one flat price per slot, and automatically recovers if YouTube drops the stream. The first day is free with no card. Monthly: $9.99 per month. StreamNeo is for YouTube and plays uploaded videos, not a live camera feed. Learn about StreamNeo, then start your free first day.
Quick Recap
Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
Rank #4
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
