SaveOnlineVideosOnline Media Toolkit

Free Online Video Compressor

Reduce video file size by up to 80% using H.264 CRF encoding. Three quality presets — light, medium, heavy — for any use case.

Click or drag a video file here
Supports MP4, WebM, MOV, AVI, MKV (up to 2 GB)

Files are processed securely on our server and deleted immediately after download.

About Free Online Video Compressor

Large video files are a persistent challenge in digital workflows. A 10-minute 1080p screen recording from Zoom might be 800 MB. A 30-second raw GoPro clip could be 2 GB. These file sizes cause slow uploads to cloud storage, fail email attachment limits, strain website bandwidth budgets, and fill up device storage quickly. Video compression solves this by re-encoding the video at a higher compression level, dramatically reducing file size while preserving enough visual quality for the intended use case. Our free online video compressor offers three CRF presets — light, medium, and heavy — covering every scenario from near-lossless archiving to aggressive compression for quick sharing.

The tool uses H.264 video encoding via FFmpeg, the industry-standard multimedia processing framework. H.264 (also called AVC — Advanced Video Coding) is the most widely compatible video codec in the world, supported by every device, browser, smart TV, smartphone, and media player manufactured in the past decade. Compression is controlled by the CRF (Constant Rate Factor) parameter, which controls how many bits the encoder allocates to each frame. A lower CRF value allocates more bits, resulting in higher quality and larger file size. A higher CRF value allocates fewer bits per frame, producing smaller files with more visible compression artefacts. Our light preset uses CRF 23 (near-original quality), medium uses CRF 28 (balanced), and heavy uses CRF 35 (maximum size reduction with visible quality reduction at full screen).

Key Features

Everything you need — no software installation required.

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Three CRF Compression Presets

Choose from three carefully calibrated presets: Light (CRF 23) for near-original quality with 20–40% size reduction — ideal for archiving and professional use; Medium (CRF 28) for a balanced 40–60% reduction suitable for most sharing scenarios; Heavy (CRF 35) for maximum 60–80% size reduction when file size matters more than pixel-perfect quality.

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Before/After File Size Display

After compression completes, the tool shows both the original file size and the compressed file size, along with the percentage reduction achieved. This lets you confirm the compression level was effective before downloading, and helps you choose a different preset if the size reduction or quality does not meet your needs.

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H.264 Universal Compatibility

All compressed videos are output as MP4 with H.264 (AVC) encoding — the most universally compatible video format in the world. The compressed MP4 plays on every modern device including iPhone, Android, Windows, Mac, smart TVs, and all web browsers without any additional codecs or plugins required.

Server-Side Processing Power

Compression is performed on our high-performance processing servers using native FFmpeg, not in your browser. Server-side encoding is 5–10x faster than browser-based compression and produces better quality results at the same file size. Your device processing power and battery level have no effect on compression speed or quality.

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Resolution and Frame Rate Preserved

By default, the compressor preserves the original video resolution and frame rate. Compressing a 1080p 30fps video produces a 1080p 30fps output — only the visual quality level and file size change. If you also need to reduce resolution, use our Video Resolution Resizer tool after compression for additional file size reduction.

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Private — Deleted After Processing

Videos are uploaded over HTTPS to an isolated server environment. After compression completes and the output file is ready for download, both the source and compressed video files are permanently and immediately deleted from our servers. No video content is stored, analysed, or retained beyond the immediate session.

How to Use Free Online Video Compressor

Get your result in seconds — completely free, no registration needed.

1

Upload your video file

Click the upload area or drag and drop your video. MP4, MKV, AVI, MOV, and WEBM formats are all supported, up to 2 GB. After upload, the original file size is displayed so you have a baseline for comparison with the compressed output.

2

Select a compression level

Choose Light compression (CRF 23) for near-original quality with moderate size reduction — best for important recordings you plan to archive or edit further. Choose Medium (CRF 28) for a good balance of quality and size — suitable for most social media and sharing use cases. Choose Heavy (CRF 35) when file size is the priority and some quality reduction is acceptable — ideal for quick drafts and previews.

3

Compress the video

Click Compress Video to begin. The video is uploaded to our server and compressed using FFmpeg H.264 encoding at your selected CRF value. A progress indicator shows upload and encoding status. Compression time depends on file size and length — a 100 MB file typically compresses in 1–3 minutes depending on video duration.

4

Compare sizes and download

When compression completes, the tool displays both the original and compressed file sizes and the percentage reduction achieved. If the result meets your needs, click Download to save the compressed MP4. If the reduction was insufficient, compress again with a higher preset. If quality is too low, retry with a lighter preset.

Compression Presets and Expected Results

Wide format support ensures compatibility with virtually any file you upload.

FormatDescriptionBest ForQuality
Light — CRF 23Near-original quality. H.264 default quality setting. Quality loss is imperceptible on most displays at normal viewing distance.Professional archiving, video editing source files, high-quality sharing20–40% size reduction
Medium — CRF 28Good balance of quality and size. Minor quality reduction visible only on close inspection of fine textures and motion. Suitable for most online viewing.Social media uploads, cloud storage backups, team sharing40–60% size reduction
Heavy — CRF 35Visible compression artefacts on fast motion and fine details. Acceptable quality for previews, drafts, and quick shares where exact quality is not critical.Quick shares, previews, draft reviews, bandwidth-limited uploads60–80% size reduction
Input: MP4, MKV, AVI, MOV, WEBMAll major video container formats are accepted as input. Source codec can be H.264, H.265, VP8, VP9, or most other modern codecs.Camera recordings, screen captures, downloads, exportsMP4 H.264 output

Who Uses Free Online Video Compressor?

Trusted by millions of users across different industries and workflows.

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Social Media Uploads

Reduce large camera or screen recording videos to upload-friendly sizes before posting to Instagram, TikTok, Facebook, Twitter/X, or LinkedIn. Social platforms re-compress uploaded videos anyway — compressing before upload at a controlled quality level produces better final results than letting the platform apply aggressive automated compression to an unoptimised source file.

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Email Attachments

Most email services limit file attachments to 25 MB (Gmail) or 20 MB (Outlook). A 3-minute screen recording or product demo video is typically 200–500 MB in original format. Heavy compression reduces this to 40–100 MB, and trimming combined with medium compression can reduce it to under 25 MB for direct email attachment without cloud storage links.

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Website and Landing Page Videos

Background videos and product demo videos embedded on web pages must be small to avoid degrading page load speed. Google PageSpeed Insights penalises pages with unoptimised video assets. Compress marketing and explainer videos with medium or heavy settings before embedding — a 10-second looping background video should be under 2 MB for good web performance.

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Cloud Storage and Backup

Compress entire video archives before uploading to cloud storage to reduce storage costs. At medium CRF 28, a 50 GB video library often compresses to 20–25 GB, significantly reducing cloud storage subscription costs. Compressed videos remain fully watchable and can be further edited if needed.

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Mobile and Tablet Storage

Free up space on iPhone, Android, and tablet storage by replacing original large video recordings with compressed versions. A 4K iPhone video recording of 1 minute is typically 400–500 MB. Medium compression reduces this to 150–200 MB with visually similar quality at typical phone screen sizes, allowing 2–3x more videos in the same storage space.

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Online Course and Training Content

E-learning creators compress full-length tutorial and lecture videos before uploading to platforms like Udemy, Teachable, or Thinkific. Platform video storage costs are typically based on total upload size. Compressing a 10-hour course from 20 GB to 8 GB reduces hosting costs and improves platform playback speed for students on slower internet connections.

Why Choose Our Tool?

Built for speed, privacy, and reliability — everything works right in your browser.

Significantly Smaller Files — Same Watchability

Medium compression (CRF 28) typically produces 40–60% smaller files that are visually indistinguishable from the original at typical viewing distances and screen sizes. For most online use cases — social media, presentations, email, streaming — the compressed output is effectively equivalent in watchability to the original while being half the file size.

H.264 Plays Everywhere

The MP4 H.264 output plays without any additional codecs on every device: iPhones, Android phones, Windows PCs, Macs, smart TVs, Chromebooks, and all web browsers. Unlike H.265/HEVC which requires hardware decoding support, H.264 has universal software and hardware decoder support, ensuring your compressed video reaches every viewer without playback issues.

Server-Side Quality Beats Browser Tools

Browser-based video compressors are limited by JavaScript performance and browser codec support, which produces slower encoding and inferior quality at the same file size. Our server-side FFmpeg implementation uses highly optimised native H.264 encoding libraries that produce better visual quality at equivalent bitrates compared to any JavaScript-based compression tool.

No Registration — No File Count Limits

Compress as many videos as you need with no usage caps, no subscription fees, and no account creation. The tool is funded by advertising and is completely free for personal and commercial use. Process single videos or an entire archive one file at a time with no queuing, rate limiting, or restrictions.

Pro Tips & Best Practices

Get the best results with these expert recommendations.

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Match compression level to the final viewing context

Choose your compression level based on where the video will be watched. Heavy compression (CRF 35) looks acceptable on a small phone screen at 360p but shows obvious artefacts on a 4K monitor at full screen. Light compression (CRF 23) is visually lossless on any display but reduces file size by only 20–40%. For social media viewed primarily on phones, medium or heavy is usually sufficient. For YouTube or presentations viewed on large screens, use light compression only.

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Combine trimming and compression for maximum size reduction

The biggest file size reductions come from combining two operations: first trim the video to remove unnecessary footage (intro countdowns, post-meeting chitchat, black leader frames), then compress what remains. Removing 30% of a video through trimming and then applying 50% compression through encoding reduces the total file size by 65% — significantly more than either operation alone.

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Original bitrate determines the compression ceiling

Compression cannot make a video better than its source. If a video was already heavily compressed (low bitrate, visible artefacts), compressing it further will make it look worse faster. The diminishing returns of compressing already-compressed video are rapid. For best results, always compress from the highest quality source available — a camera original rather than a previously compressed export.

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For repeated compression, always start from the original

Each compression pass removes more quality information. If you compress a video to medium quality, then later compress the medium output to heavy quality, the result will be significantly worse than compressing the original directly to heavy quality. Always keep the original file and compress fresh from the original each time you need a different quality level or file size target.

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Frequently Asked Questions

Everything you need to know about Free Online Video Compressor.

How much can I reduce my video file size?
Light compression (CRF 23) typically reduces file size by 20–40%. Medium compression (CRF 28) reduces by 40–60%. Heavy compression (CRF 35) reduces by 60–80%. Actual results depend on the source video — videos that are already heavily compressed (e.g., downloaded from YouTube or social media) will compress less than original camera recordings, which have much more redundant data to remove.
Will compression make my video look worse?
Light compression (CRF 23) produces virtually imperceptible quality loss at normal viewing distances. Medium compression (CRF 28) has minor quality reduction visible only on close inspection of fast-moving detail. Heavy compression (CRF 35) shows noticeable artefacts — blocky edges, colour banding, and motion blur — particularly on scenes with fast movement or high detail. Choose the lightest compression that achieves your required file size.
What video formats can I compress?
The tool accepts MP4, MKV, AVI, MOV, WEBM, and most other common video containers as input. The source video codec can be H.264, H.265/HEVC, VP8, VP9, or most other modern codecs. All output is delivered as MP4 with H.264 encoding for maximum compatibility across all devices and platforms.
How long does compression take?
Compression time depends on video length, file size, and upload speed. H.264 encoding at CRF 23–35 processes at approximately 2–5x real time on our servers. A 5-minute video (100–500 MB) typically compresses in 1–3 minutes. Upload time adds to this — uploading a 500 MB file over a 50 Mbps connection takes approximately 80 seconds.
Is my video uploaded to a server?
Yes. Video compression requires server-side encoding — it cannot be done in your browser at acceptable quality and speed. Your video is uploaded over HTTPS to our isolated processing server, compressed using FFmpeg, and the compressed output is made available for download. Both the source and output files are permanently deleted from our servers immediately after your download session.
What is CRF and how does it work?
CRF (Constant Rate Factor) is the primary quality parameter for H.264 video encoding. It controls how many bits the encoder allocates to each frame based on the complexity of the scene content. A lower CRF value means more bits per frame, higher quality, and larger file size. A higher CRF value means fewer bits per frame, lower quality, and smaller file size. CRF 23 is H.264's default quality level. Our presets use CRF 23 (light), 28 (medium), and 35 (heavy).
Why does my compressed video look worse than expected?
Several factors affect compression quality. If the source video was already compressed (e.g., exported from YouTube, social media, or a previous compression pass), it contains less redundant data and will show more artefacts when compressed further. Videos with lots of fast motion, film grain, or high-frequency detail (outdoor scenes with foliage) are inherently harder to compress cleanly than static or slow-moving content.
Can I compress 4K video?
Yes. The tool handles 4K (3840x2160) and even higher resolution video files. Compressing 4K video takes longer than HD video due to the larger amount of data to process — a 5-minute 4K video may take 5–10 minutes to compress depending on original bitrate. The output remains at 4K resolution unless you also use our Video Resolution Resizer to scale down to 1080p for additional file size reduction.
Is there a maximum file size I can compress?
The tool supports video files up to 2 GB. For files larger than 2 GB, use our Video Trimmer to split the video into shorter segments, compress each segment separately, then re-combine them in a video editor if needed. Alternatively, downloading the video at a lower quality setting from the source (if it is a recorded stream or downloaded video) can make the file small enough to compress directly.
How is this different from changing the video resolution?
Compression (CRF encoding) reduces file size by increasing the quantization of each video frame — more compression artefacts at the same resolution. Resolution reduction (downscaling to 720p from 1080p) reduces file size by reducing the number of pixels per frame. Both reduce file size through different mechanisms. Resolution reduction is more aggressive for large file size reductions (80%+) but also reduces sharpness at larger screen sizes. Compression is better for maintaining resolution while achieving moderate size reductions.