Video Converter

💡 Tip of the Day

Compress images to reduce file size.

What is Video Format Converter

Video Format Converter turns your clips into the format and size you need without leaving your browser. Stuck with a file your editor, phone, or social app won’t accept? The free Video Format Converter by FlexiTools.io lets you drag and drop a video, pick MP4, WEBM, MKV, or AVI, choose a resolution, trim by seconds, and download the result. In the next 60 seconds, you can load a file, set the output format and 1080p/720p/480p or keep Original, trim start and end, click Convert, and watch the progress bar until your download is ready.

How to Use Our Video Format Converter

  1. Add your video
  • Drag & drop a file into the upload area or click Browse Files. Supported inputs include MP4, AVI, MOV, MKV, WEBM, FLV, and WMV.
  1. Choose output settings
  • Select an Output Format (MP4/H.264, WEBM/VP9, MKV, or AVI) and set Resolution to Original, 1080p, 720p, or 480p.
  1. Optional: Trim by seconds
  • Check Trim Video, then enter Start (s) and End (s). Only that segment will be converted.
  1. Convert and download
  • Click Convert. Track progress in the bar and percent readout. When Conversion Complete appears, click Download or start a New Conversion.

Why FlexiTools.io Offers the Best Video Format Converter

Private, in‑browser conversion

Your video is processed on your device. No sign‑ups, no uploads, no waiting on a server queue.

Simple controls that cover real needs

Pick the format, pick the resolution, and trim by seconds. The UI stays out of your way.

Clear feedback and control

Progress percent, a visual bar, status messages, and Cancel when you need to stop and revise settings.

Fast handoff to your workflow

A direct Download button and New Conversion keep your tasks moving.

FlexiTools.io vs typical alternatives

  • FlexiTools.io: In‑browser conversion and download - Alternatives: Required uploads
  • FlexiTools.io: MP4, WEBM, MKV, AVI outputs - Alternatives: One format only
  • FlexiTools.io: 1080p/720p/480p + Original resolutions - Alternatives: Hidden or fixed sizes
  • FlexiTools.io: Built‑in trimming - Alternatives: Extra steps in another tool

A Deeper Look at Video Formats, Codecs, and Resolution

Video files bundle two big ideas: the container and the codec. The container is the “wrapper” that holds video, audio, subtitles, and metadata. Examples include MP4, WEBM, MKV, and AVI. The codec is the compression method that actually encodes the video frames and audio samples. When you pick MP4 (H.264), you’re choosing the MP4 wrapper with H.264 video inside. For WEBM (VP9), the wrapper is WEBM and the video codec is VP9. This distinction matters because some platforms care more about the codec than the wrapper.

MP4 (with H.264) is widely compatible and a safe choice for most devices and websites. WEBM (with VP9) is efficient and delivers smaller files at similar quality for many scenes, especially at HD resolutions. MKV is flexible and can hold many tracks, but some mobile apps don’t preview MKV by default. AVI is older and can be useful for legacy needs, yet its feature set is limited compared to newer containers. Picking the right combination depends on where the video will play. For a quick overview of containers and codecs, see MDN’s guides on media container formats and video codecs.

Resolution controls pixel dimensions. Downscaling from 4K to 1080p or 720p can dramatically cut file size because there are fewer pixels to encode. If your target screen or social slot is 720p, encoding at 720p is smarter than keeping a higher resolution that will be downscaled on the fly. For email or messaging, 480p is often enough, and the smaller file travels faster. If you need maximum clarity on large screens, keep Original, but remember that higher resolution means longer processing time and larger files.

Trimming is a simple but powerful step. By selecting Start and End in seconds, you export only the slice you need. This shortens processing time, reduces file size, and keeps your final cut focused. Not sure where to trim? Take a quick pass — you can always run a second conversion if you want a longer or shorter segment. Clean cuts also help when you’re preparing multiple versions of a clip for different platforms.

Why do file sizes vary so much? Beyond resolution, the codec’s efficiency and the content of the video matter. Shots with lots of motion, noise, or tiny details take more bits to look good. Static scenes compress more easily. That’s why two 60‑second clips at the same resolution and format can have very different outputs. If your target is a strict size or duration, lowering resolution and trimming off unused parts usually gives the biggest win before you worry about deeper encoding tweaks.

Compatibility tips:

  • For cross‑platform sharing, MP4 (H.264) is still a great default. It plays almost everywhere.
  • For modern browsers and web usage, WEBM (VP9) can be smaller at the same perceived quality.
  • If a tool or device rejects a file, try another container with a common codec — e.g., MP4 instead of MKV — keeping the same resolution.

Performance and reliability: video conversion takes CPU, memory, and time. Larger files and higher resolutions need more of each. Keep the tab open, avoid heavy background tasks while converting, and let the progress bar reach 100%. If a conversion stalls, try a lower resolution or a shorter trim segment, then re‑run. If a result has playback issues, convert to MP4 (H.264) at 720p — that combination works in most software.

Audio tracks ride along inside the container. If you notice silent output, the original may use an uncommon audio codec. Try a different output format that your target app prefers. For social or chat, a short MP4 (H.264) with standard stereo audio is often the most reliable.

Two practical playbooks:

  • Social clip: Trim to the highlight, choose MP4 (H.264) at 720p, convert, download, and post. You’ll get a good balance of clarity and size.
  • Archive to share: Keep Original resolution, pick MKV or MP4 depending on your workflow, and convert. If a recipient can’t play the file, re‑encode to MP4 at 1080p.

You don’t need deep encoding knowledge to get a solid result. A clear target — where the video will play and what size you can accept — guides your choices. Pick the format your destination likes, pick a resolution that fits the screen, trim the clip, and you’re done.

Pro-Tips for Getting the Most Out of Video Conversion

  • Start with MP4 (H.264) at 720p for quick sharing; switch to WEBM (VP9) for smaller web files if your audience supports it.
  • Trim first — shorter clips convert faster and keep files lean.
  • If compatibility is a question, downscale one step and try MP4; it’s the most widely accepted pairing.
Which formats can I convert to?
You can export to MP4 (H.264), WEBM (VP9), MKV, or AVI. Input support covers common types like MP4, AVI, MOV, MKV, WEBM, FLV, and WMV. If a file won’t load or fails to play after conversion, try MP4 (H.264) and a standard resolution like 720p.
Does the tool upload my video?
Conversion runs in your browser. Large files and higher resolutions may take longer and use more memory, so keep the tab open during processing. When the progress hits 100%, click Download to save the result.
How do resolution choices affect quality and size?
Downscaling (for example, Original to 1080p or 720p) reduces pixels and usually shrinks file size a lot. 480p is a compact option for messaging or small embeds. Keeping Original preserves detail but produces larger files and longer conversions.
How does trimming work?
Check Trim Video and enter Start and End in seconds. The converter exports only that range. Make sure Start is less than End. Trimming a clip first is the fastest way to meet platform time limits and reduce file size.
Why is my output bigger or smaller than expected?
Scene complexity, codec choice, and resolution all change size. Motion‑heavy clips need more data than static scenes at the same settings. If you need a smaller file, trim and downscale; if you need sharper output, keep a higher resolution or switch to a more compatible format like MP4 (H.264).