Video Compressor
Compress MP4, MOV, and MKV with CRF controls or target an exact file size. Nothing uploads to a server, so you can compress any unreleased footage or personal videos without risking theft from a data breach.
Good for hitting a file attachment limit before sending or submitting a video.
▸▾Large files take time — keep the tab open
Video compression runs entirely in your browser. Keep the tab open and active while it runs — closing or switching tabs will stall or stop processing. On iPhone and iPad, iOS limits memory per browser tab: videos over 100 MB at Original resolution may cause the page to restart. When you pick Original on mobile with a large file, the tool warns you before you start — choose 720p or 480p for a safer run, or use a desktop browser for full quality on large batches. On Android, Chrome throttles background tabs which can stall long encodes — stay on this tab. On desktop, a 500 MB file can take 5–15 minutes depending on your CPU. High-motion footage (sport, gaming) compresses less than screen recordings. H.265 produces 30–50% smaller files than H.264 but requires a modern device for playback.
Drop files or a folder here
or click to browse · paste from clipboard
Accepts .MP4, .MOV, .WEBM, .AVI, .MKV, .WMV, .TS · Up to 1,000 files
How it works
Drop your files
Click to browse, or drop your files. For best results, process 1-5 files at a time.
Choose settings
Adjust quality, format, and other options to match your needs.
Click Convert
Files are processed in the browser. Nothing uploads. No risk of data breach.
Download
Download files individually or grab all at once as a ZIP.
How to Compress Videos?
In layman’s terms, compressing a video means shrinking its file size to save storage space and make it easier to share or upload without degrading playback quality. There’s a delicate balance at play here.
With ConvertYard, the compression happens in the browser. Open or drag/drop the video, pick a target size and quality, wait for it to compress, then download the compressed version. One difference between this tool and most I’ve seen online is that it works in your browser. I tested it with WiFi turned off, and it compressed even large MP4 files over 2 Gigabytes.
One issue with cloud-based video compressors is twofold. First is the privacy issue. Even though they promise to delete the videos after a certain time period, there is always a risk of a data breach or a leak, and if you’re working on a client project or something that, let’s say, you don’t want to fall into the wrong hands, it will stay on the internet forever.
The second issue is that larger videos take longer to process because you have to upload them before the compression process starts. That depends on your internet speed; if you have a choppy connection, compressing a 500 MB to 1 GB file will take a long time.
Here’s the basic workflow using ConvertYard.
- Open or Drag/Drop a video file into the converter (supports MP4, MOV, WebM, AVI, MKV)
- There are several options - the easiest is choosing the ‘file size target’ or a smaller resolution (720p, 480p, or 320p).
- Click Compress, and the process happens locally in the browser.
- Download the ZIP or file.
Most videos shrink 50–90% with no visible quality loss, especially if the original was recorded on a phone at a high bitrate.
I’ve tested compressing large videos (over 6 gigabytes of raw camera footage) on a desktop (on a Mac laptop) using Chrome, and it took about 5 to 8 minutes to compress that one file at 1080p. The result? The original 6.4 GB video file is compressed to 300 MB, or over 85% compression at 1080p. With the H.265 compression turned on, it increased the compression to 97% (205 MB file) without degrading quality.
Compressing videos from an iPhone
Videos shot with an iPhone are typically recorded in HEVC (H.265) within a .MOV wrapper. The high bitrate for these videos (especially for 4K) results in high-quality videos but larger file sizes. A single minute-long 4K video can be as much as 400 MB.
A few things worth noting.
- Safari will refresh if you try to compress a large video (over 400 MB), especially if you choose the original or 1080p resolution. In my tests, it handles anything under 400 MB as long as you choose the 720p resolution. One option I’ve built into the tool is using the target size. If you want better quality, choose the larger size options (100 or 200 MB), or go with the smaller sizes if you want to target a specific size (like 25 MB on Gmail).
- On desktop, Safari handles larger files better (up to 1 GB without auto-refreshing). If you want to compress larger videos on mobile, use other browsers like Chrome, which can handle larger files (up to 1.5 GB on mobile) without refreshing.
- You’ll notice that Safari on iOS disables the original resolution and 1080p because of the refresh issue, so use 720p.
- Unfortunately, you cannot compress with an H.265 video codec on Safari for larger files, even those over 50 MB, because the browser will crash or refresh. For maximum compression, use the target size feature. The purpose of the H.265 codec is simply to further reduce file size without degrading quality, so using the target size solves the issue if you’re targeting a range.
Compressing videos from an Android
Modern Android phones record in H.264 or H.265 using an MP4 file format. However, manufacturers like Samsung, Google, and OnePlus use different encoding algorithms. Fortunately, compressing videos on an Android phone allows for more leeway with larger files. I’ve tested files over 1 GB without the browser crashing, and that’s with an older Samsung phone over 5 years old.
Common target sizes
- 10 MBHit the WhatsApp and Telegram share limit. Drop the file, click compress.
- 25 MBStay under Gmail's 25 MB cap. Send your video as a real attachment, not a Drive link.
- 50 MBUnder the Slack free-tier cap. Fits Discord standard, Asana, Notion, and most team tools.
- 100 MBHit Discord Nitro Basic and most LMS upload limits. Full 1080p quality at 100 MB.
- 200 MBLong 1080p clips that still transfer fast. Covers WeTransfer and most file-sharing tools.
- 500 MBArchival compression for long recordings. Keeps 1080p quality across hour-long footage.
- 1 GBNear-lossless compression for 4K recordings and long-form professional footage.
Frequently asked questions
Yes. Compress one or ten files. However, with .mov files over 1.5 gigabytes, you may get an FS error, which means the browser is out of memory. For smaller files under 1 GB, you can follow the 1-to-5 file principle.
It supports these formats: MP4, MOV, WebM, AVI, MKV, WMV, and TS. However, the output is always MP4 (H.264 or H.265). You can play an MP4 file on any device without additional software, and most video editing software supports it.
The compression level parameter controls the Constant Rate Factor (CRF) of the H.264 video codec. CRF balances quality and size. For example, Small (CRF 18) is nearly lossless but reduces size only slightly, while Medium (CRF 23) is the H.264 default and a good trade-off between quality and size. High (CRF 28) is heavily compressed but much smaller than Medium quality. Maximum (CRF 35) is for archiving, and size matters more than quality.
H.265 (or HEVC format) is the newer codec that compresses videos (at least with my testing MOV files) up to a whopping 116% difference with no noticeable difference in quality. If you’re using a video or sharing it with someone who uses a newer laptop or mobile device (like the newer iPhone or Android), you can use this format. Use the older H.264 format for devices released before 2016.
Target size, as its name implies, aims to compress the video to a specific file size. It does this by calculating its duration, then determining the exact bitrate needed to reach the target file size. The video is encoded twice: first, an analysis pass, then an output pass. It's similar to how professional video software does it (using a 2-pass VBR encoding). When the file approaches its target size, it remuxes the container files instead of re-encoding.
No, compression does not reduce your video's duration. It only reduces the quality of each frame. If you choose a resolution such as 720p, your video will be downscaled during compression. However, your video will still be the same duration.
Video compression takes longer because it needs to process multiple frames. For example, your 60-second video at 30fps has around 1,800 frames, whereas an image compressor only has one frame; thus, the compression is much faster.