CLIPTextEncodeFluxWeight

Flux is a two-brain model. Its T5-XXL encoder is the language brain - it's why Flux understands full sentences - and its CLIP-L encoder is the "soup of words" brain that SD1.5 people already know. The built-in ComfyUI text encoder feeds both of them from one prompt, but it gives you no way to say "I want the T5 to chill out and the CLIP tags to pull harder." That's the exact gap CLIPTextEncodeFluxWeight was built to fill: two text boxes, two strength dials, one conditioning output.

This node is from a small lineage that started in August 2024, right after Flux launched, when someone on r/StableDiffusion complained that Flux "desperately needs prompt (strength) guidance" and a dev replied "saw your post and agree, so made it real fast." This is that idea as a finished, slightly cleaner node. Don't expect it to do anything more than that.

What it actually does

Give it a CLIP (the one you load with DualCLIPLoader using a flux prefix), plus two separate prompts: clip_l for the tag-style text and t5xxl for the natural-language sentence. It tokenizes each into the right encoder, encodes them together, and hands you a CONDITIONING that goes straight into your KSampler's positive input - and often the negative too, since Flux Dev has no real negative prompt.

Then the part the built-in node won't do: it scales slices of the encoded conditioning tensor by clip_l_strength and t5xxl_strength, then bakes guidance into the conditioning so you don't need a separate FluxGuidance node. One node does what ComfyUI normally needs two for.

The inputs that matter

• clip_l - comma-separated tags, the SDXL-style phrasing. Stuff like photorealistic, cinematic lighting, portrait.
• t5xxl - the full-sentence prompt. This is where Flux's natural-language magic lives.
• clip_l_strength (default 500) - the eyebrow-raiser. Five hundred. That default is tuned for whatever workflow the author (leeguandong) was running, and it is not a sane starting point for yours. Set it to 1.0 first, then push it up and see what actually changes. This knob is a blunt post-hoc multiply on the conditioning tensor, not a faithful "re-weight this encoder" - its effect is empirical, so treat it like a seasoning dial, not a spec.
• t5xxl_strength (default 1) - same idea for the T5 side.
• guidance (default 3.5) - the usual Flux guidance scale. The community default is 3.5, though many people run 2 or lower for less "Fluxmaxxed" faces; if you're new, leave it alone at first.

Output is a single CONDITIONING, which wires straight into KSampler.

Install

Tiny pack, no dependencies, no model downloads - it reuses the CLIP model you already load. Via ComfyUI Manager, search "ComfyUI_FluxClipWeight" and install. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/leeguandong/ComfyUI_FluxClipWeight

Then restart ComfyUI. There's a linked example workflow on OpenArt in the README if you want the author's starting point - worth grabbing, because it'll show you what sane values for those knobs look like.

Where people get burned

The clip_l_strength = 500 default is the trap. If you drop this node into a workflow and don't touch it, you're multiplying the first slice of your conditioning by 500, which is almost certainly not what you want. Set it to 1 and dial from there. Also worth knowing: the node prints its entire token pipeline to the console (Tokenizing clip_l and t5xxl texts, full tensor dumps) - noisy, harmless, but don't panic at the wall of text. And keep expectations calibrated: this is a one-file, lightly-maintained pack with essentially no community footprint. For plain Flux prompting you don't need it at all - reach for it only when you actually want to lean on one text branch over the other.