Compress a clip so it fits comfortably within a chat app's attachment size limit before you upload it.
This compressor finds the highest-quality MP3 that fits under Discord’s free upload limit. You give it a recording; it works out the maximum bitrate from the duration, picks sensible channel and sample-rate settings, encodes, and measures the real size — stepping down until the file is truly under the limit.
As of August 2026 Discord’s free upload limit is 20 MB (up from 10 MB), with Nitro Basic at 50 MB and Nitro at 500 MB; server boosts can change what a given server allows. Presets are provided for each, so you can match the limit you actually have.
Size = bitrate ÷ 8 × duration, so the budget is bitrate = limit × 8 ÷ duration. The tool uses a 1.5% safety margin for MP3 frame overhead, picks the largest legal MP3 bitrate that fits, switches to mono below roughly 112 kbps (speech: 80 kbps) and to 22.05/16 kHz at very low rates for better quality per bit, then encodes for real and checks the byte count. If it is still over, it steps one bitrate down and repeats (up to five times). Sizes use decimal megabytes (1 MB = 1,000,000 bytes), the stricter and safer interpretation for upload limits.
Share recordings in a channel.
Post songs that stream inline.
Share previews with a community.
Meet a server’s limit.
| Limit | 20 MB (Discord) (decimal MB, editable) |
|---|---|
| Method | Largest MP3 bitrate that verifiably fits |
| Verification | Real encode + byte count |
| Modes | Music or Speech |
20 MB for free accounts as of August 2026; 50 MB for Nitro Basic and 500 MB for Nitro. Older or unchanged servers may still enforce 10 MB, so check yours.
MP3 files do, with an inline player.
Discord's exact upload limit depends on your server's boost level and can change over time — check your server's current limit, then use the target size field above (or the Under 10MB / Under 25MB presets) to match it.
MP3 at a controlled bitrate is the most universally compatible way to hit a specific file size on any device or platform.
No — everything happens locally in your browser. Nothing is sent to a server.
This tool runs entirely in your browser using the Web Audio API. Nothing is uploaded, stored or shared — there is no server to send your file to, so it works offline once the page has loaded.
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