Free tool
Seed Explainer
Paste any seed and we'll show you what changes if you keep it, change the prompt, or switch the sampler — the most common iteration mistake.
Keep seed + same prompt + same model: identical image, every time. Use this to confirm a render is reproducible.
Keep seed + change one prompt word: nearly identical composition with the new concept swapped in. The fastest way to iterate without losing your composition.
Keep seed + change sampler or CFG: different image. Seed only fixes the starting noise — the path to the final image depends on every other setting.
Keep seed + change model: completely different image. Seeds are not transferable between checkpoints.
Tip: write your seed down once you get a render you like. Synexa shows it under every generation and lets you re-apply it in one click.