DaVinci Resolve has no "target file size" control — the Deliver page gives you exactly two documented ways to put a ceiling on the size of a render, and both of them are bitrate controls, not size controls. Everything else you can change (codec, resolution, profile, number of passes) affects the final size only as a side effect.
That is worth stating first, because most advice on this problem is written as if Resolve had a field where you type "under 25 MB." The reference manual's rendering chapter is 33 pages of render parameters, and a target-size field is not one of them.
The controls that actually bound the size
Every line below is the manual's own wording, from the Deliver page render settings.
| Control | Official wording |
|---|---|
| Restrict to X Kb/s | "You can choose Automatic, or select a maximum data rate with which to export." |
| Use Constant Bit Rate | "If the Format and Codec you've specified allows you to switch between variable and constant bit rate output, this checkbox lets you force video to render at a constant bit rate." |
| Maximum Bit Rate | "(Does not appear for all codecs) Codecs such as Kakadu JPEG 2000 let you specify a maximum bit rate, in Mbits per second, with which to encode the delivered video." |
| Disk space used after render | "Shows the new disk usage based on the specified range of the current session that you're rendering." |
Two qualifiers you cannot drop. First, Restrict to X Kb/s is not always on screen. The manual introduces that whole group of controls with a condition: "If you choose MP4 as the format, or QuickTime with H.264, H.265, or VP9 as the codec, additional options appear, described below." Pick ProRes or DNxHR and you are in a different settings panel entirely.
Second, the pair of disk indicators is genuinely confusing in the official text. Right above the one quoted in the table, the manual describes "Disk space currently used" as "Shows the amount of disk space available on the target volume" — the label says used, the description says available. The two do not agree, so read the numbers on your own system rather than trusting either phrasing.
Why Resolve never quotes you a number in MB
Because Blackmagic's documentation never commits to one. That is not an oversight you can work around — it is the shape of the product.
- No default is published for Restrict to X Kb/s. The manual's entire description of it is the sentence in the table: you can choose Automatic, or set a maximum.
- The social presets carry no published bitrate either. The manual lists what the YouTube, Vimeo, TikTok and Dropbox presets set — Format MP4, Video Codec H.264, Audio Codec AAC — and stops there. The What's New page says only that "Compression settings have been developed based on each site's best recommendations, meaning your videos will be optimized for visual quality and playback speed." No numbers.
- The one data rate Blackmagic does print is for audio. The H.264 Master preset "defaults to rendering in single clip mode, with the Format set to QuickTime, and the Codec set to H.264... Audio defaults to the Codec being AAC with the Data Rate set to 320 Kb/s and the Bit Depth set to 16."
So if you need a file under a hard cap — an email attachment, an upload form — Resolve will not do the arithmetic for you. You either compute a bitrate yourself and type it into Restrict to X Kb/s, or you render once and shrink the result with something that does take a size target. For the specific numbers any given platform enforces, see the limits explainers rather than guessing from inside Resolve.
Shrinking a render that is already too big
Re-rendering from the timeline costs you the whole export time again. If the file exists and is merely oversized, compressing the finished file is usually the faster path.
Try it right here
Runs in your browser. Your file is not uploaded anywhere.
This runs in the browser tab, so the render never leaves your machine — the same privacy property you get from exporting locally in the first place. It targets a size, which is the thing Resolve's own controls will not do. The video compressor and the rest of the browser tools are listed on the tools page.
If you would rather fix it at the source, these are the officially documented knobs, in the order I would touch them:
- Restrict to X Kb/s — the only direct ceiling, subject to the format and codec condition above.
- Resolution — "The output resolution for rendering. This setting defaults to Timeline Resolution."
- Entropy Mode — CABAC is described as "A higher-quality algorithm that yields better visual quality at lower bandwidth, at the cost of being more computationally expensive to process and play." Note that Blackmagic spells the other option "CALVC" in its own manual.
- Multi-pass encode — "(Available for QuickTime H.264 and H.265) ... Single pass is faster, but multi-pass yields superior results when quality is important. When you enable Multi-pass, the number of passes performed is automatic." The QuickTime qualifier is the manual's, not mine: it does not offer this for MP4.
Gotchas Blackmagic states outright
Cutting an H.264 file and exporting it will re-encode it. In the Supported Formats and Codecs list dated July 2025, the Codec Passthrough column is a dash for H.264, H.265, MV-HEVC, AV1 and VP9 on every platform. That column, per the official footnote, "Indicates if codec renders can be sped up by reusing the original source video essence if there are no effects or color changes to the clip." Formats like DNxHR and ProRes in a mov wrapper do have it; the delivery codecs most people use do not. That is the mechanism behind "I changed nothing and the file still came out different" — more detail in bypass re-encode, explained.
The H.264 and H.265 Master presets output QuickTime, not MP4. Both preset descriptions say the Format is set to QuickTime. If you expected a .mp4 and got a .mov, that is the preset behaving as documented.
Above 4K, the free version is out. The same codec list states: "Encoding video resolutions >= 4K is only supported with DaVinci Resolve Studio." Blackmagic's product page separately says the free version lets you "edit and finish up to 60 fps in resolutions as high as Ultra HD 3840 x 2160," and it does not define whether UHD counts as 4K here — see the 4K export question and check the official documentation before planning a delivery around it.
On Windows, the free version's H.264 and H.265 exports are profile-limited. The codec list's exact value is "8-bit OS-supported profiles. More profiles and GPU acceleration in Studio." That is a restriction on which profiles you get, not a block on exporting.
FAQ
Can I set a target file size in DaVinci Resolve? No. The documented controls are a maximum data rate ("Restrict to X Kb/s") and a Constant Bit Rate checkbox. Neither takes a size in MB.
What bitrate should I enter to get under a specific size? Blackmagic publishes no guidance and no defaults for this, so any number you find online is someone's arithmetic, not an official recommendation. Work out the bitrate from your duration, or compress the finished file with a tool that accepts a size target.
Why is the Restrict to X Kb/s field missing? Because of the format condition. Those extra options appear when you choose MP4 as the format, or QuickTime with H.264, H.265 or VP9 as the codec. Other codecs show a different set of controls, and some expose a "Maximum Bit Rate" in Mbits per second instead.
Do the YouTube and TikTok presets keep the file small? They set a consistent recipe — MP4, H.264, AAC — but Blackmagic publishes no bitrate figures for them, only that compression settings were developed based on each site's recommendations. Check the resulting file rather than assuming a ceiling.
Does trimming an already-exported MP4 in Resolve avoid re-encoding? No. H.264, H.265, AV1 and VP9 all show a dash in the Codec Passthrough column of the official codec list, so the video essence is re-encoded rather than copied.
Wording cited from the DaVinci Resolve 21 Reference Manual, the Supported Formats and Codecs list dated July 2025, and Blackmagic's product pages, checked 16 September 2026. Blackmagic changes these documents between versions — verify against the current official documentation before relying on them.
