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TutorialJune 3, 2026·5 min read

How to compress OBS recordings on Windows without uploading anywhere.

A one-hour OBS session at 1080p can easily hit 10–30 GB. Before you can share it, send it to a client, or upload it to YouTube — you need to compress it. Here's how to do it locally, fast, without touching a cloud service.

Why OBS files are so large

OBS records in near-lossless formats by default (MKV, MP4 with CQP encoding) to preserve quality. That's great while you're recording — but it makes the output files enormous. A 30-minute gaming session at 1080p/60fps in CQP 18 can produce a 15–25 GB file. That's not a file you share or store long-term — it needs to be compressed.

Why cloud tools are the wrong answer

Uploading a 20 GB file to a cloud compressor defeats the point. You're waiting hours for the upload, paying a monthly subscription, and your footage — gameplay, client calls, private content — is sitting on someone else's server. For most OBS users, that's exactly what they're trying to avoid.

The local solution: GPU compression

Your GPU already has a dedicated hardware encoder sitting idle: NVENC on NVIDIA, AMF on AMD, Quick Sync on Intel. These encoders compress H.264/H.265 video 5–10x faster than your CPU and produce files 70–90% smaller than the raw OBS output — with no visible quality loss at the right settings. ReelNox Studio uses these encoders directly. You drag in your OBS files, set your quality target, and it compresses them locally in a fraction of the time it would take to upload anywhere.

How to do it — 4 steps

1Download and install ReelNox Studio (Windows 10/11, signed installer — no cloud, no account)
2Open the Compress panel and drag your OBS recording into the queue
3Select H.265 (HEVC) for best compression, or H.264 for maximum compatibility — ReelNox auto-detects your GPU
4Hit Compress. A 10 GB OBS file typically compresses to 800 MB–2 GB in under 5 minutes with GPU acceleration

What to expect

A 1080p/60fps OBS recording at CQP 18 (default) typically compresses to 8–12% of its original size with H.265 at CRF 24 — so a 15 GB file becomes roughly 1.2–1.8 GB. Quality is visually identical for most content. Gameplay footage with fast motion may show slight softening at very aggressive compression — use CRF 20 if quality is critical.

Download ReelNox Studio →Windows 10/11 · €19.90 lifetime · No subscription · Signed installer

About

Patrick Chen — indie developer behind Sublimearts.io. I built ReelNox Studio because I kept reaching for cloud tools to compress OBS recordings and hating every second of it.