Hit strict 10 MB, 25 MB, and 50 MB limits without artifacts. This playbook covers why uploads fail, the bitrate math behind every preset, and the workflows our compressor automates for you.
Drop a file, pick 10, 25, or 50 MB, and FitToMB will handle two-pass encoding plus optional downscaling. Swap presets or enter a custom value inside the embed.
Formula: Pick your target size → calculate bitrate → run a two-pass H.264 encode with AAC 96 kbps → downscale only if bitrate dips too low → cap frame rate only when motion is simple.
Email inboxes and chat apps have hard attachment caps-Gmail tops out at 25 MB before shunting files to Drive, Outlook hovers around 20-34 MB depending on tenant rules, and Discord's free tier blocks anything above 10 MB.
Inline previews rely on MP4 + H.264 + AAC. Stick with our defaults so Gmail and Yahoo render the thumbnail instantly. Review our Gmail guide and Yahoo guide for exact caps.
Envelope overhead, MIME boundaries, and thumbnails consume 5-10% of the envelope. That's why we suggest targeting 20-23 MB for Gmail attachments instead of 25 MB flat.
Every attachment piles on more MIME overhead. Compress the hero asset with FitToMB and link secondary clips via cloud storage.
Containers wrap encoded audio and video. Codecs (H.264, HEVC, AV1) define how frames are compressed. Bitrate is the amount of data allocated per second across both streams.
Approx. size (MB) ≈ (video_kbps + audio_kbps) x duration_sec ÷ 8 ÷ 1000
FitToMB's calculator subtracts audio automatically so you only worry about the video bitrate. Our two-pass encode meets the target size while preserving detail in motion-heavy moments.
MP4 + H.264 is the safest bet for inbox previews. HEVC and AV1 shrink files more but often skip inline playback.
Stay at the highest resolution you can while maintaining ≥ 0.07 bits per pixel. If bitrate dips below that threshold, drop to 720p or 480p.
Cap at 30 fps for most explainers. Reserve 60 fps for action or gameplay when the platform allows larger caps.
Start with duration. These rules of thumb match the heuristics inside FitToMB-follow them manually or let the tool pick automatically.
Our default stack-H.264 (libx264) + AAC 96 kbps + two-pass ABR-hits exact file sizes while staying inbox-friendly.
Want to understand the trade-offs? Dive into the Understanding bitrate guide for graphs and examples.
Drop your file into FitToMB, pick 10/25/50 MB, and download the optimized MP4. Queue up to six files at once-each auto-deletes after an hour for privacy.
Need automation? Mirror our two-pass pipeline in ffmpeg.
ffmpeg -i input.mp4 -c:v libx264 -b:v 3200k -pass 1 -an -f mp4 /dev/null \ && ffmpeg -i input.mp4 -c:v libx264 -b:v 3200k -pass 2 -c:a aac -b:a 96k output.mp4
On iOS, use the FitToMB Shortcut to send clips straight from Photos. Android users can share to the web app and select presets. Downscale in the Photos app first if your LTE upload is slow.
| Channel | Target | What works best |
|---|---|---|
| Email (Gmail, Outlook, Yahoo) | 20-23 MB for Gmail, 20-25 MB for Yahoo/Outlook | MP4 + H.264 + AAC. Follow the Gmail attachment workflow and Yahoo tips to avoid Drive/Dropbox fallbacks. |
| Chats & communities | 8-10 MB (Discord free), 25 MB (Slack uploads) | Target an exact MB with two-pass ABR to skip server-side recompression. Reference the marketer best practices for channel-specific messaging. |
| Landing pages & hosted video | 50-100 MB mezzanine | Keep moov atom at the front for fast start. Link visitors to How FitToMB works so they understand the downscale + two-pass combo. |
Compare outputs at different bitrates using the reusable stills included below. Each shows the benefit of two-pass targeting on motion-heavy scenes.
Preserve quality by maintaining bitrate per pixel and using two-pass targeting. Downscale only when bitrate dips below 0.07 bits per pixel.
Plan for ~3300 kbps video + 96 kbps audio. The inline calculator and FitToMB's presets do the math instantly.
Stay with H.264 for inline previews. HEVC/AV1 shine on high-capacity hosting where compatibility is guaranteed.
Anything above ~25 MB triggers Drive. Target 20-23 MB or follow the Gmail guide for fallback behavior.
Use high-contrast colors, thicker outlines, and avoid micro text. Our marketer-focused guide shares creative tips that compress gracefully.
Yes. Uploads are encrypted in transit and auto-delete one hour after completion. See the privacy details in the footer.
Absolutely-bookmark the calculator for planning shoots or export targets.
Use the reusable stills and table in this guide, plus the deeper explanations in Understanding bitrate.