How to Compress 4K Video Without Losing Quality

Updated September 26, 2026

Re-encode to H.265 at a quality setting between 18 and 23, keep the resolution, and check the result before you delete anything. On our 11-clip test set, VideoRecompress's default (H.265, quality 23) on an NVIDIA GPU cut 254.9 MB to 128.4 MB and no file came out bigger. Savings depend on the source, so try one of your own files first.

−50 %total size of our 11 test clips with H.265 on an RTX 3080 (254.9 MB → 128.4 MB)

0 / 11clips that came out bigger: when an encode is larger, the app keeps the original

−33 %median saving of H.265 over H.264 at the same quality setting (11 pairs)

Measured in September 2026 at VideoRecompress's default settings on a Ryzen 9 3900X with an RTX 3080. The test clips run from DV to 1440p; the 4K timing further down comes from 4K iPhone HEVC footage.

Why 4K files are so large

A 4K frame (3840 × 2160) holds 8.3 million pixels, four times a 1080p frame. Cameras record at a high bitrate so nothing is lost while filming: the 4K iPhone clips we tested run at about 30 Mbit/s, roughly 225 MB per minute. That bitrate suits recording, not years of storage.

Which codec: H.265, AV1 or H.264

H.265 (HEVC)RecommendedIn our 11 pairs at the same quality setting, H.265 files were a median 33 % smaller than H.264. Phones and TVs play it; Windows needs the HEVC Video Extensions. NVIDIA, Intel and AMD graphics cards encode it in hardware.

AV1Smaller still: an iPad clip came out 42 % smaller than H.265 at the same VMAF. It took 15 times as long, because the RTX 3080 has no AV1 encoder and AV1 ran on the CPU. RTX 40 cards, Intel Arc and AMD RX 7000 encode AV1 in hardware.

H.264 (AVC)Plays everywhere, but makes the biggest files. If your 4K footage is H.264 today, re-encoding it to H.265 is where most of the space comes from.

Every clip, with file sizes and quality scores: HEVC vs H.264, measured.

Which quality setting (CRF) to use

The quality setting, called CRF, trades size for detail: a lower number keeps more detail and makes a bigger file. VideoRecompress's presets cover the useful range:

Preset	Codec and CRF	Use it for
Wedding / Event Archive	H.265 · CRF 18	Footage you cannot shoot again
Phone Video Archive	H.265 · CRF 23	Everyday phone and camera video; the default we measured above
Security Camera Archive	H.265 · CRF 28	Bulk archives where size matters most
Maximum Savings	AV1 · CRF 35	The smallest files, if you can wait: slow without an AV1 graphics card

At the default setting our clips scored VMAF 89 to 99 on the CPU encoder (VMAF compares the new file with the source; 100 means identical). The lowest score came from an interlaced DV tape. Before a big batch, click Test Encode (10s) in the app: it encodes 10 seconds from the middle of a file and shows the size and quality.

GPU or CPU

8–17×faster H.265 encoding on an RTX 3080 than on a Ryzen 9 3900X (6 clips)

128.4 / 138.1 MBtotal of our 11 test clips at the default setting, GPU against CPU

16.3 → 9.5 sfor a 17-second 4K iPhone clip, now that the app decodes 4K on the GPU as well (September 2026)

Quality stays close. The GPU's VMAF score was within 2.5 points of the CPU's on 8 of the 10 clips we could score, and lower on a grainy GoPro clip (92.2 against 98.8) and an interlaced DV tape (85.1 against 89.3). For footage like that, or your most important files, switch to the CPU encoder; for a big archive, the GPU's speed matters more. Intel Quick Sync and AMD AMF encoders are supported, but we have not measured them.

Step by step: compress a folder of 4K video

Add the folderDrag a folder in or pick files. The app lists each file with its codec, resolution, bitrate and size on disk.
Pick a presetPhone Video Archive for everyday footage, Wedding / Event Archive for footage you cannot reshoot, Maximum Savings for the smallest files.
Leave hardware encoding on AutoThe app encodes on your NVIDIA, Intel or AMD graphics card when there is one, and on the CPU when there is not.
Click StartEach new file is checked when it is done. If it came out bigger than the source, the original is kept instead.
Check before you deletePlay a few of the new files before you remove any originals. VideoRecompress writes new files and leaves the originals where they are.

How much space you save: 11 clips measured

These are the 11 clips behind the numbers above, at the default setting (H.265, quality 23). Savings run from nothing, where the source was already efficient and the original was kept, to 96 % on an old DV tape.

Clip	CPU (Ryzen 9 3900X)	GPU (RTX 3080)
Timelapse, 1440p	−3 %	original kept
Drone, 1440p	−47 %	−48 %
GoPro, 1080p	original kept	−31 %
Lecture recording, 1440p	−55 %	−36 %
Travel video, 1080p	−21 %	−5 %
Wedding camera, 1080p	−49 %	−40 %
DivX film	−14 %	−35 %
DV tape (PAL)	−93 %	−96 %
Phone video, 720p	−60 %	−65 %
SD TV episode	−13 %	original kept
Web video, 720p	−23 %	−8 %
All 11 clips	254.9 → 138.1 MB (−46 %)	254.9 → 128.4 MB (−50 %)

None of these clips is 4K. For 4K footage, run Test Encode (10s) on one of your own files before the whole folder.

HEVC vs H.264: how much space you really save (measured) Compress 4K iPhone Video Faster on an NVIDIA GPU (2026.2.17)

Shooting with a GoPro or a drone? Read how to remove noise from action camera footage with AI Video Enhancer Studio before you compress it.

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